A Wookie I Did

[Relique du Madde]

as apes are to humans, so are Klingons are to Wookies.

Not really.

Remember Worf de-evolved into a venom spitting crustacean not a chimp.

So...

Worf = Xenomorph
Wookie = Yetti

 

[Scott DeWar]

Why would Worf de-evolve into a chimp? he was not human.

A venom spitting crustacean would only be one possible backward engineering path he could have taken. there might be other chains of going backward, just as there were many possible chains of going forward.