In Africa, at some point, some Graboid eggs hatch, but in secret. Eventually the hatching leads to six Ass Blasters and two active Graboids. Instead of constantly hunting, as the American species does upon birth, these Graboids and Ass Blasters focused on propagating their species, forming a nest with over a dozen eggs in a cave.
While looking for cheetah cubs to poach, Johan Dreyer and Basson stumble upon the cave containing the Ass Blaster colony and nest. Basson falls into the cave and before he can be lifted out, is killed by an Ass Blaster. Dreyer catches the creature on camera and hoping to use a live Ass Blaster to get a lot of money on the black market, Dreyer's boss Erick Van Wyk enlists famous monster hunter Burt Gummer and his new sidekick Travis Welker to help him capture a live Ass Blaster under the guise of working for the South Africa government. However, while Burt and Travis take the job, they are given substandard weapons for the job. As they are preparing, a couple of paleontologists locate the skeleton of an African Graboid and are shortly thereafter devoured by one of the living Graboids. When shown the attack spot, Burt's suspicions that they are dealing with more than just Ass Blasters are confirmed and after seeing the Graboid skeleton, realizes that these Graboids are more dangerous than the North American breed.
After Amahle finds a Graboid egg somewhere, two Ass Blasters attack the safari lodge that night to get it back. Seeing them, Thaba faces one with a machete, killing it with a slash from his weapon as it charges him. Hearing the attack, Burt rushes over and shoots the other Ass Blaster, confused by their behavior as the jeep they were attacking didn't have its engine on to draw them in. The second Ass Blaster survives Burt's shot and grabs Thaba, taking him with it. Burt and Dreyer chase the Ass Blaster to a bridge where Thaba has been dropped in the middle. As Burt rushes to the badly injured man's help, the Ass Blaster attacks him but flies off when Burt fires at it with his rifle. The Ass Blaster flies off with Thaba and Burt runs out of ammo firing after it. It then attacks the Land Cruiser with Dreyer, but Burt grabs Thaba's dropped machete and throws it into the Ass Blaster, killing it. The Ass Blaster's body falls off the bridge and Burt and Dreyer return to the lodge to order an evacuation. Burt, Dreyer and Van Wyk go after the nest while Travis is left behind because he was too busy partying to help during the Ass Blaster attack.
Finding another Ass Blaster near the cave that Basson died in, Burt realizes that they've found the Ass Blaster colony. He deploys a flare to distract the Ass Blaster and Dreyer tries to tranquilize it. The tranquilizer has no effect and to Burt's shock, the Ass Blaster ignores the flare and charges them. Trying to get away, Dreyer gets his hand jammed in the Land Cruiser's door and broken. Burt shoots the Ass Blaster before it can kill Dreyer and it flies off for an aerial attack. Seeing this, Burt waits until the Ass Blaster is flying directly at him and shoots it with a machine gun given to him by local veterinarian Nandi. Burt's fire kills the Ass Blaster and triggers the chemicals in its body to explode, causing its remains to drop on top of Dreyer, killing him. Finding an intact Graboid egg amongst the Ass Blaster's remains, Burt realizes that the Ass Blaster was trying to protect its nest and bloodline so the species would continue. Van Wyk reveals himself as a poacher, locks Burt inside a lion cage they brought along to hold a captured Ass Blaster and takes off with the egg, intending to sell it on the black market. After several hours of being locked up, Burt is rescued by Travis who discovered his plight through the cameras in the cage. Due to Burt's delirium, he believes a Graboid is after them and trying to get away from it, they break the fuel line on their jeep and have no more fuel to replace what they lost.
At the lodge, Nandi, her daughter Amahle and friend Baruti come under attack by another Ass Blaster looking for the egg in Amahle's possession. Separated from Nandi, Amahle and Baruti end up trapped in the lodge kitchen by the Ass Blaster. Baruti's pistol fire has no effect on the Ass Blaster, but before it can kill them, Nandi kills it with two arrows from behind.
Burt and Travis begin looking for Van Wyk, eventually finding the now-empty machine gun he took from Burt and his crashed Land Cruiser. They are able to retrieve a shotgun, a rifle and a phosphorus grenade from the wreckage and notice the footprints of Van Wyk and a serpentine creature. Continuing their search, they find an injured Van Wyk carrying a metal cooler with his stolen egg inside near the nest. To their shock, a serpentine creature pulls the cooler from Van Wyk into the cave. Moments later the empty cooler is shot back out. Detecting a Graboid, Burt orders Van Wyk on top of a nearby rock and is shocked to find out that the serpentine creature is actually a Grabber, one of a Graboid's tentacles. In this breed, the tentacles are sentient and can detach from the host Graboid. The Grabber attacks Van Wyk, but Burt shoots it, destroying the creature. However, as Van Wyk believes himself safe, the Graboid known as the Queen Bitch emerges from the ground and eats Van Wyk despite Burt shooting the Graboid.
Realizing that the Graboid is intent on protecting the eggs inside the cave to propagate its species, Burt decides that they need to get inside the nest and destroy it. Travis convinces Burt to let him go instead and Burt arms Travis with the phosphorus grenade with a warning to use it if he is attacked. Travis gives Burt his cell phone as he goes and Burt calls pilot Den Bravers to come pick them up in his helicopter and to bring them gas for their jeep and more ammo. After confirming that they need heavy weapons, Bravers decides to equip his helicopter with rocket pods he got off of a MIG fighter in a war to help the situation. While Burt contacts Bravers, Travis enters the cave, using flares to light his way. After stumbling across human remains from the Ass Blasters' victims, Travis finds the nest to find it contains well over a dozen Graboid eggs. An Ass Blaster spots him and attacks. Travis flees the cave, dropping his flare to distract the Ass Blaster and his armed grenade next to it. The grenade kills the Ass Blaster and allows Travis to get out safely.
Burt and Travis realize the cave is too well protected by the Graboids and Ass Blasters for them to safely get into and head away from it to meet up with Bravers and his helicopter. Bravers arrives, but attracts the Queen Bitch's attention by blaring loud music as he flies in. Three Grabbers attack and kill Bravers' co-pilot before Burt can stop them. As they deal with that loss, the Queen Bitch goes after Bravers herself and Burt fires at her with his rifle while Bravers uses a shotgun against her. The Queen Bitch apparently gives up, but instead attacks Bravers from the other side of the helicopter as he and Burt desperately try to stop her with their weapons. The Queen Bitch comes out of the ground and grabs Bravers with her tentacles, swallowing him whole. Seeing this leaves Burt despondent as they are now out of ammo, stranded and have no way to destroy the nest which they need to take out to keep more Graboids from being born. However, Travis points out the helicopter's rocket pods as a way to destroy the nest and Burt decides to use a cattle stampede as a cover to reach the helicopter. The trick works and the two are able to safely board the helicopter. Burt discovers that the rocket pods have ten rockets loaded and decides to use them all on the nest. After a brief conversation with Travis about something that happened in Florida 40 years before, Burt targets the nest and fires all of the helicopter's rockets at it. The rockets destroy the nest and all of the Graboid eggs inside it. Moments later, Bravers reveals himself to still be alive, having blasted the insides of the Queen Bitch with his shotgun until she spit him up. Detecting the Queen Bitch returning, the three quickly flee in the helicopter. Bravers returns them to their jeep which they fix with his help and refuel with gas he brought them. Though Bravers has to leave to attend to other duties, he leaves Burt with an FN MAG machine gun to use against the remaining Graboids and Ass Blasters. Afterwards, Travis finally reveals to Burt that he is Burt's son and while he is trying to process this, a Grabber tries to attack Travis from behind. Burt quickly kills it with his Colt Peacemaker and they take off for the lodge in the jeep. A second Grabber grips the jeep's axel and tries to stop them from escaping, but Travis kills it with the FN MAG, allowing them to get away.
Nandi and Baruti realize that there must be some kind of reason for the Ass Blasters continuing attacks on them and decide to abandon the safari lodge in favor of the nearby village for safety in numbers. As they leave, the last Ass Blaster climbs on the corrugated metal roof above them and Baruti fires at it with his shotgun. Baruti's fire kills the Ass Blaster, but as they reach the jeep, they discover the other Graboid is after them too. Though a concrete slab protects them from the Graboid's initial attack, it survives the collision and comes back around for another attack run. Spotting a gas can on the jeep he is hidden behind, Baruti comes up with an idea: he sets the jeep on fire and places a burning cloth hanging out of the gas cap of the vehicle. He then sends it straight at the Graboid while Nandi readies a flaming arrow. As the Graboid emerges from the ground and grabs onto the front of the jeep, Nandi fires her arrow into the burning cloth in the gas cap, pushing it into the gas tank and detonating the tank and car. The explosion, with the Graboid having just grabbed onto the front of the vehicle, kills the Graboid. Nandi, Baruti and Amahle quickly flee in Baruti's jeep and Nandi finds the Graboid egg her daughter found and realizes why the Ass Blasters and Graboids are after them so much. Arriving at the village, they find no sign of people and checking the general store, Nandi finds a man who is dragged into the ground and eaten by the Queen Bitch.
Emerging from the store, Nandi finds Amahle missing and following her screams, finds her trapped in the village ring with two Grabbers and the surviving villagers doing their best to distract the creatures from her. Burt and Travis arrive, having found the lodge abandoned and realize that the Grabbers won't attack as long as Amahle has the egg as its the last of the Graboid bloodline, but they can't rescue her as there's too much danger of hitting Amahle if they fire at the Grabbers. Spotting a motorcycle, they quickly come up with a plan: Travis will take the motorcycle to distract the Grabbers while Baruti rescues Amahle and Burt lays down covering fire. The plan works: Travis is able to get the egg from Amahle and toss it to Nandi. One Grabber lunges at Burt who kills it with the FN MAG while the other latches onto the back of Travis' motorcycle. However, Travis drives close to the brick walls of the ring, shredding the Grabber to pieces. At the same time, Baruti is able to get Amahle to safety.
Following the failure of her Grabbers, the Queen Bitch herself attacks, but Travis is able to dodge her attack. Spotting the daily storm, Nandi comes up with an idea which she shares with Burt: in order to catch worms for bait, Amahle uses an electricity trap, an earthworm zapper. Nandi suggests doing the same but on a larger scale with the Queen Bitch: draw her off and then set up some metal poles with wire running between them to catch a lightning strike and divert it into the ground and the Queen Bitch. With 13 minutes until the storm arrives, Burt and Nandi have Travis lead the Queen Bitch to the river with his motorcycle to buy them the time they need as they set up the trap. As Travis distracts the Queen Bitch, the villagers and Burt set up the poles and wires and Nandi places the last Graboid egg on the village altar as a further lure. Once they are all set, Nandi shoots a flaming arrow into the sky to signal Travis who sees it and leads the Queen Bitch back. Travis leads the Queen Bitch into the trap then quickly flees before the lightning strikes can begin. As the villagers, Burt and Travis watch, a lightning bolt hits the trap, travels through the contraption and finally into the ground and the Queen Bitch. Crackling with electricity and in intense pain, the Queen Bitch rears up out of the ground where Burt, Nandi and Baruti unload their weapons into her. A second lightning strike destroys the last Graboid egg and a third goes straight down the throat of the Queen Bitch. The direct lightning strike blows the Graboid apart, killing her.