This is really cute! I noticed you want critique, I hope this is okay?

It's a bit top heavy, his legs would need to be thicker to carry the weight if he indeed uses his legs, and his arms are a bit to forward on the body plan, the shoulder joint would be a little bit back, you'd see some of his chest bone and clavicle, even if he did slouch like I assume he does.

But it reminds me of a mudskipper I found as a kid. It freaked me out when it jumped away hehe