1999-2000: I only drew side faces of Yoshies, with a full body. The bodies were very long, and I didn't draw hands.
2001: Still didn't draw hands, added a second eye so that it wasn't always a side view.
2002: Added an "eyelid" part to make it make more sense.
2003: Revamped my Yoshi style by drawing it closer to what Yoshies looked like at the time. The nose is spherical. First time I was drawing hands on Yoshies rather than the typical "mittens".
2004: Removed the eyelids again.
2005: Improved the style. First time I've drawn Yoshi feet.
2006: Changed the sphere nose so that it's not a complete sphere. Was based on LunaYoshi's style. This style change allowed for a wider range of emotions (specifically, anime emotions).
2007-2008: Improved the style.
2009: Added the eyelids again.
2010-2011: Changed the eye to make it more anime-ish.
Here's another one. It isn't as accurate because this one is me drawing how I *used to* draw Yoshies during those years, and so they look better than they should.