Boredom and curiosity.

[Vipershark]

he was originally inspired by the Mario 64 Bowser but I really like the more vibrant colors.

I think the super vibrant colors are fine, but the issue (to me, at least) is with with the neon blue lines. They're so bright and used in so many places that would normally be dark (a lot of outlines and such) to the point where it almost makes them seem like highlights and makes most of the sprite look strange.

It's kind of like he's meant to be in the movie Tron with such bright highlights.
Having a bright palette is cool but I'd suggest changing the brighter blue shades to something else or at the very least making them a lot darker because they stand out too much to me and kind of overtake the actual highlights. It has too much contrast, I guess.