What happened to brown Yoshis?

The only way to find out for sure is to ask the guy himself, but it sounds pretty traumatic so he not remember the whole thing
 
No, when he undergoes the transformation, his brain becomes mutated into a Donkey Kong brain. So, it's likely that he won't remember the experience, or he'll retell it in a twisted way, making Donkey ape noises while doing so. Of course, you need to give him more bananas than normal.
 
Or a plane ;P
 
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Nope, he definitely said that me and him should buy a boat together.
 
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