Security-Maintaining-Treehouse-Response-System or S.M.T.H.R.S (Pronounce: Smothers) is a high-technological treehouse that Tommy and his gang built to hang out in.
He is voiced by Lewis MacLeod.
He served to protect the gang from disturbers such as Donnie, who had previously destroyed their first treehouse. At the beginning, the treehouse was a luxurious free time place for the children to enjoy things such as video games, comic books, favorite shows, makeup and endless supplies of food.
He resembles a normal tree, but he has a metal bunker at the base of the branchs, which has two wooden platforms on it, and his leaves resemble Tommy's head. When his leaves were blown off, he was revealed to have a bird house at the top.
- S.M.T.H.R.S' is a reference to the fictional and famous robot HAL 9000 from 2001: A Space Odyssey.