Hi,
I finally got around to check these animations. Unfortunately, I hit many bugs in the kart exporter (yeah, STK is like that atm xD) so I couldn't commit any of them. But here are some general comments :
* Adiumy : great losing animation; I'm not sure about winning however, because the kart will still be moving when the animation is played. Also he does a weird flip near frame 98. It's also maybe not a good idea to make him come out of the kart because then you see he has no legs

* elephpant is good (and already committed a while ago)
* eviltux : he has issues, the rig doesn't seem to work, the skeleton moves but not the model
* gooey : the animation is good. the texturing makes him a bit more interesting. however the new texturing og
the kart makes it very flat.
* gnu : animation OK
* hexley : great!
* mozilla : good animation. the textures are broken but that should be easy to fix (mozilla is pink here)
* mr ice block : animation is good, but the wiki says the ending animation must be loop-able, so not sure it can work
* puzzy : seems good too!
* tux : animation ok. the rig could use with improvements, his arm and chest get a bit weirdly distorted
* wilber : animation ok. but not sure it will fit. remember the kart will continue moving when the animation is played
In general, also make sure to respect the markers on the wiki. In many locations, you use "Start-Winning" when it needs to be "start-winning" (I'm pretty sure case matters)