Yoshi's posed a little strange because he is 'being ridden' Obviously, since I haven't made the correct Mario/Luigi/Toad/Peach poses, it looks...Unnatural...
Of course, I'll eventually make the right poses, so it won't look odd, but for now...it does...
I'm still thinking about having Yoshi be 'layable' (as in, normal Poses like Mario & Luigi). The only thing really 'holding me back' from the decision is 'Yoshi riding a Yoshi,' which is probably why we got the Second toad in New Super Mario Bros. Wii, instead of a Yoshi (Well, that and color coordination wouldn't really work...)
In all honesty, I just drew it in Paint, then animated the frames in Microsoft Gif Animator, but it was a lot harder to make than it looks (Since I tried to get it to resemble Yoshi...a lot, haha)