Frazetta Man
One common recurring figure from Frank Frazetta (Sr.) paintings has come to be known affectionately as Frazetta Man: a caveman more primitive and primal than Neanderthal, hairy ape-like subhumans who show up to battle swarthy, muscular warriors and/or menace scantly clad nubile maidens they logically shouldn't even be attracted to (at least not anymore than you'd be attracted to one of their women).
The 1983 animated movie Fire and Ice (not to be confused with this) is Frazetta's sole foray of into cinema, but the pinnacle of his artform: an improbably voluptuous heroine clad only in a very small bikini (despite her icy homeland) faints a lot while being repeatedly chased by hairy ape-men, who in at least one scene where she is bathing clearly want to bury their clubs.
These grunting, Stone Age parodies have a certain soft spot in the hearts of old-school neckbeards. Frazetta Man represents one of the oldest visual depictions of the goblin, orc or even ogre, depending on how big and savage they are, and their starring role in some of the most iconic of pulp-era fantasy settings. If you want to give your Dungeons & Dragons game a different touch, or find a use for Terra Primate, you can do worse than look for inspiration amongst the ranks of Frazetta Man.
The fact that a minor Chaos God named "Phraz-Etar" exists, and that Apemen are known to exist in the Southlands, could point to Phraz-Etar being the Chaos God the Apemen of the Southlands worship, sacrificing human Southlanders and Arabyans they capture in raids to him.