Zyzzybalubah is a malevolent but lonely male alien who brainwashed Conky into making his own name the secret word and launched the Playhouse into outer space to capture the occupants within. He calls anyone he captures his "friends" (such as Yvona) but Pee-wee (upon arrival and capture on Zyzzy's homeworld) furiously sets him straight with the following explanation:
"WELL, YOU'VE GOT THE WRONG IDEA! Friends are people that you care about and who care about you! YOU BROUGHT US HERE WITHOUT EVEN ASKING US IF WE WANTED TO COME! And you haven't exactly been treating us the way friends should be treated!"
After realizing his mistake, Zyzzy explains his reasons for capturing everyone and says that everyone on his planet hates him, then turns off the force field holding the captives (he had turned it on in an attempt to recapture Yvona, who escaped him with the intention of warning Pee-wee and his friends about their captor). Earlier, Zyzzy claimed that he was watching Pee-wee for some time, noting how much fun the man-child has in the place. Zyzzy also claimed that it was an honor and very flattering to have the secret word be his name before this statement, but we clearly know otherwise from the beginning scene. It is implied by Yvona that Zyzzy has kept her locked in a cage and forced into servitude by him for a very long time. It is implied that he is the ruler of the planet that he forces Pee-wee and the others to visit, as Yvona states that everyone on her planet has been enslaved by Zyzzy and forced into servitude. In one scene, two ant warriors are at his flank, but they just float uselessly and do not respond to what their master is saying.
His base of operations is a mysterious crystalline structure of unknown construction, though it only appears in two scenes. His window to other planets and temporal dimensions is a crystal ball-like "viewing globe" of sorts. He also seems to have a technological interest in Conky, as he was the one that brainwashed him.
Played by George McGrath, he is the second character to be performed by this actor. He resembles the character Megamind, and even more suspiciously, is extremely similar in appearance and hostile behaviors of the Talosians (Star Trek Original Series). His vocabulary is also eerily similar to Zim from Nickelodeon's Invader Zim TV series, which was released years after Playhouse. Zyzzy is the only villainous extraterrestrial life-form that Pee-wee encountered in the series.
Zyzzy acts like your typical deranged, over-confident alien ruler found in sci-fi cartoons and TV shows. Initially he is very domineering, loudmouthed, bossy and forceful, demonstrated by silencing Pee-wee after he makes a joke about Zyzzy contacting him on the Picture Phone ("Good connection! You sound next-door!"), and by forcing Yvona into servitude and locking her in a cage. After being told the truth of what friendship really is, he backs down and changes for the better, learning that one must be nice to have lasting friendships.
However, his initial attitude is actually the result of loneliness from being disliked by everyone on his planet.