This was one of my favorite bosses in Yoshi's Island. You wait for Kamek to turn the frog huge like usual.
Wait a minute... I'm turning smaller?
And of course, I'm frog lunch.
So you get to fight the frog's belly. Somehow he eats shyguys but you also have to dodge stomach acid.
But you get to shoot "giant" eggs.
Until there's a "tummy ache".
You don't get barfed back up though. The look on Yoshi's eyes says it all. I hope he took a bath after that.