My entry. Down to the wire too, but it's finished.
Conceptually, I combined a chimpanzee, an octopus, a whale to a very very minor extent (those aren't teeth, they're more like baleen- otherwise this thing would have been way too menacing.) The result was a multi-limbed, bulb-headed creature with wicked posture, polydactylism and a penchant for eating the things that make your pool green. A proud day for evolution to be sure.
Conversely, in addition to obvious advantage having 8 limbs provides, ideally it would possess the octopus's brain and with any luck the combined chimpanzee and octopus cognitive abilities, and the opposable thumb (which is handy) .
I'm currently calling him Ferdinand. Has a better ring to it than "the octopus-chimp-whale-thang."
A little bit of mixed media here. Created in ZBrush, retouched/painted in Photoshop, and Illustrator for those little tech-esque decorations.