Super Smash Bros. Ultimate Ripping Project

[ninetalescommander]

I manage to rip Squirtle model for Smash U, but I don't know how to export it without the armature rotating and shrinking.

I assume you are using Crossmod to rip the models, right? If so, don't export them in Blender, use Noesis to convert them to whatever format you want, personally I do DAE. The only downside is this causes all the mesh names to be reset so if you want to restore the names, you have to then put them in Blender and rename them individually. If there is a way to convert with Noesis and keep the mesh names, sadly I don't know what it is.
Also, word of advice, if you are using Crossmod always export to SMD, any other format I've tried either crashes or the armature/uv maps come out messed up.