I'm torn between considering this thread as harmless silliness and ignoring it, and making a serious suggestion.  Consistency has never been a priority...

My favorite critter to represent has always been the Lambasaurus Rex.  You can see a small image of it here http://www.franz.com/~smh/rex.jpg and see the interpretation here http://www.franz.com/~smh/lambda.jpg .
Perhaps an animated gif that slowly blend oscillated between the two would be optimally cute.

Warning -- I snarfed both of these images from the web long ago -- can't remember where -- but I don't know if they might be encumbered by any IP rights.  In any case, if some list member with more time than sense wanted to tackle the project, new unencumbered images could easily be created.