They made him. They raised him. Now he's coming out to play.
Monkey Boy is one of those European imports that dwells in cinematic obscurity thanks to some heavy edits and poor repackaging. Originally billed as 4-part miniseries called Chimera in the UK, the US release is actually a heavily edited version of director Lawrence Clark's initial vision.
Having only seen the trailer myself I can't really speculate on how much of that vision was lost in the import though according to other reviews I've seen online, the general consensus seems to be that it strips out much of the characterization that takes place in the beginning of the miniseries.
Much like the upcoming film Splice with Adrien Brody, Monkey Boy explores the taboo world of genetic research as scientists at a fertility clinic scheme to create something that is half human and half monkey (thus the US re-title). The creature (Chad) manages to escape at some point thanks to his superhuman strength which, of course, instigates a manhunt for his return. From there the film explores the Chad's struggle with his childlike naivety and more primal instincts as he brutally bludgeons and stabs his way back to the clutches of his creator. Stabs? Oh yes, seems this chimp has a bit of slasher in him and... wait, is that a Freddy Kruger sweater he has on?
The effects (from what I've seen both in photo stills and footage) are an eerily convincing collaboration between makeup artist Bob Keen (Hellraiser, Nightbreed) and Peter Elliott, an animal trainer with experience consulting for film. Lest we forget, the creature himself is portrayed by actor Douglas Mann who played a similar simian role in Greystoke: The Legend of Tarzan, Lord of the Apes.