The Gatecleaner is a direct parody of the "Gatekeeper" character from the game "Nightmare". He has become a recurring character on The Spoony Experiment, and even seems to play a prominent role in his current story ark. His appearance is relatively simple; a black robe and hood. Like the Gatekeeper, he is always seen in a dark background with a lot of smoke.
The Gatecleaner made his first appearance in The Spoony Ones review of "Nightmare", where he introduced himself as the "nephew" of the Gatekeeper, and demanded that Spoony review the rest of the "Atmosfear" games.
Afterwards, in Spoony's second review of Pumpkinhead, the Gatecleaner forced Spoony to complete said game (with the help of LordKat), in order to leave the "blag-ole".
He later appeared in his review of Ultima VI, in which he met up with Chuckles the Jester, and recruited him for some kind of "revenge" he was planning, apparently to punish Spoony for not reviewing the "Atmosfear" sequels like he was supposed to.
After Spoony was re-merged with his black lantern self, he was sent back to the "blag-ole", where the Gatecleaner forced him to watch an alternate ending to the Pumpkinhead game.
The Gatecleaner made an appearance in Suburban Knights, in which he could apparently be called by someone picking up a rock and saying "give me light". After giving the TGWTG crew the directions they needed, it was revealed that he apparently had a wife, who was on "rock waiting" to ask him to pick up croutons. Whether or not this will become a recurring gag remains to be seen.