We have a few tanks that shoot up neon yellow mushrooms all the time. They are cool when they are erect and look like normal mushrooms, but once they pop up they tend to die in a few days and shoot their spores all over the tank covering everything in a yellow powder. They are cool at first, but tend to make the tank look crappy because they die so quickly and their spores. Springtails and mites tend to break them down quickly though. Keep in mind, if you put mushrooms in your tank, you will probably never be able to get rid of them without sterilizing the entire tank. They won't harm the frogs though.
Kevin Hoff