I personally like Yoshi. I picked him for my file planet/icon thingy. It's just the inherent weirdness of a male dinosaur... frog... thing... that lays eggs.
Then again, when the core idea of the series is that mushrooms make you stronger, and we have people like Waluigi and Birdo, and the main villain has a crush on the damsel in distress and is a good parent on the side, egg-laying dinofrogs aren't that strange.