Can anyone tell me what this little guy is?

$5 nice steal

 

For sure is a kenya tree. This is what they look like when they are all closed up. Mine gets even stubbier than that at night. These guys will constantly be dropping branches once they hit a certain size and the parameters are right for them , so be careful. They can easily take over a tank. They also have a toxic slime that some other corals don't like at all, so when you add another coral don't place it too close and keep an eye on it, but for the most part you shouldn't have a problem. I have zoos, mushrooms, anthelia, devil's hand and a frogspawn with my kenya in a 10gal which is pretty mush tight quarters and everything seems fine Good Luck. Congrats on your first coral!