>>21037997HIPPO! Forget the bear! A hippo works perfectly as a starter and still fits within that river trope! Sure Hippopotas is a thing, but he's not water!
How about this? Since Hippos tend to swim just at surface level and sometimes have smaller animals rest on top of it, how about a third stage that has a sandy back? It would look like a floating island if it were to swim. Sort of a water-Torterra, if you will. You can throw a few clamshells or starfish on there and suddenly you even fit the Beach theme that was voted on.
The earlier stages can be fat and cute.