very hard to choose
because this is my least favorite dex so far but honestly nothing has been able to top the croc so far (specifically Fuecoco; the other two stages are much worse imo, even if Skeledirge is decent)
I actually prefer Slither Wing and Clodsire a fair amount more, but i'm going by >>52780682's rules and only mentioning wholly original designs because Slither Wing is just a slightly modified Volcarona and Clodsire is Quagsire on four legs with shitstains and an extendable ribcage 