What is that yellow stuff growing next to my pineapple

Question

It wasn't there yesterday and I don't know what it is. I have no idea of what it could be.

Answer 1

They're Leucocoprinus birnbaumii, a saprobic mushroom that isn't uncommon in pots and houseplants in pots. It won't harm your plants nor you, unless, that is, you eat them, because they're toxic if consumed. If you don't like the look of them, snap them off and dispose of them, but they will very likely recur, if not this year, then next. More info can be seen here: Leucocoprinus birnbaumii.