Professor Van Pelt's Army is a band of fierce mercenaries that serve Professor Professor Van Pelt in the jungles of Jumanji. When Jumanji transformed its board game form into a new video game design, members of the army were represented on the start-up title screen, as a solo motorcyclist and a motorcycle and sidecar combo.
In the backstory of the game, Van Pelt leads a group of mercenaries and the NPC (non-playable character) Nigel in the search for the Jaguar's Eye, which he had a great obsession with. Van Pelt succeeded in retrieving the Jewel from the Jaguar statue, and, as a result, was possessed by the Jewel's power and gained the ability to control Jumanji's wildlife, while also bringing a curse upon the land. That night, Nigel succeeded in stealing the Jewel from Van Pelt in an attempt to return it, although Van Pelt's pet vulture altered him to the theft, and Van Pelt was furious at Nigel betraying him, ordered his henchmen and the wildlife to retrieve the Jewel and kill anyone standing in their way. Nigel subsequently gives the Jaguar's Eye to individuals sucked into the game, who assume the identities of the game's protagonists, and tasks them with returning the Jaguar's Eye to its statue.
When the Jaguar's Eye ends up in the possession of high school students Spencer Gilpin, Anthony "Fridge" Johnson, Bethany Walker, and Martha Kaply, who took the identities of game protagonists Dr. Smolder Bravestone, Moose Finbar, Professor Shelly Oberon, and Ruby Roundhouse, respectively. Van Pelt's men promptly cornered the group in Jumanji's Bazaar, but were unable to detain them for long due to Smolder Bravestone's intense self-defense and the prompt rescue by Seaplane McDonough (Alex). Van Pelt arrived, furious that the players escaped and after one of the henchmen informs his boss of the protagonist's escape, and as a result, Van Pelt ensures him that he will not fail him again, killing him with a scorpion.
Van Pelt left a handful of men to guard the Transportation Shed to prevent anyone from having an easier journey to the Jaguar Shrine. Ruby Roundhouse (Martha) then tried to distract the men guarding the shed, but since they only responded with pre-programmed scripts, she was forced to use her dance fighting to defeat them.
When Bravestone (Spencer) returned the Jaguar's Eye to its statue and the five protagonists shouted "Jumanji" to beat the game, Van Pelt disintegrated, leaving his army either leaderless or defeated and respawned back to the game start. Once the quartet returned to the real world, they destroyed the Jumanji game cartridge with a bowling ball, thus either destroying the video game once and for all and precluding Professor Van Pelt and his army a chance to ever return or cause any harm to anyone again.
On the official site of Jumanji: Welcome to the Jungle, the game Rhino Run has minions of Van Pelt as dangerous hazards. They appear randomly as both individual Motorcyclists and Motorcycle & sidecar combos on the fixed routes and can only be avoided but can also be passed through when the characters ride an Elephant when picking up a powerup. As playable characters pass through levels, the game speed increases and makes the bikers and other hazards even harder to avoid.