I never would have thought of making Lowly Worm. And I'm sure it's possible to do a decent Yoshi, just make the belly bigger, give the body more of an S shape, make the neck a tad longer, beef up the leg where it meets the body. I've attached a quick picture of my revision to your Yoshi, CrossEyed7, though I don't know how much better it is (and I don't have an EA account).
Me, I decided to try Trogdor. The arm's horribly borked whenever it moves, but other than that, it's not too bad.