The Tribesmen are a group of people who work for Papu Papu. Their first appearance was in Crash Bandicoot, where they did nothing more than be obstacles and enemies to get in Crash's way, by either ramming him with their shields or blocking him from proceeding forward. They have large hair, and a green skirt. Like their leader they are technically neutral characters but are usually portrayed as antagonists.
They were later seen in Crash Twinsanity at the start of the game. They proceeded to kidnap Cortex under the orders of Papu Papu. However, Crash eventually saved him from their clutches.
Their appearance stayed relatively the same in all of their appearances in the series. By Twinsanity, they seem to be more advanced, as they are seen with binoculars and boats. This tribe practises human sacrifice, which is shown when they start chanting when Cortex falls down into the river and falls off the waterfall. If a Tribesman with binoculars see Crash they will start jumping up and down, alerting the other tribesmen and Crash will be hit with spears.
In the "N. Sane Trilogy", remaster of the first the tribesmen repeat the same role which they had in the original. They also appear in Nitro Fueled featured in a cutscene before Papu Papu's challenge, and additionally they can be found in Skull Rock battle arena.
Tribesmen also appear in the Thumpin' Wumpa Islands level of Skylanders Imaginators as NPCs, speaking fluent English in a way slightly reminiscent of a stereotypical Californian surfer and unlike in other games are friendly helpful characters rather than antagonists.
In the Willy Wombat bible, Aku Aku was described as a member of the tribe. 
In Japan, the Jungle levels variant, and Hog levels variant are separate.