Irony: During the invention exchange Joel blows his nose using tissue that has the cure to the common cold printed on it.
Subverted Kids Show: The 'bots literally subvert Joel’s attempts to show kids how to make an arts and crafts Gaos head by dispensing mischievous advice to the audience. Their suggestions include eating paste, drawing on their bedroom wall with a permanent marker and cutting pictures out of public library books. Finally, when Joel takes Servo away for a time out, an unattended Crow announces that the word of the day is "booger."
The KTMA version provides examples of:
Continuity Nod: Crow is still "frozen" like he was in the previous episode.
It Is Pronounced "Tro-PAY"/You Say Tomato: While reading the opening title, Joel pronounces it as "GAY-os" (and a few others, such as "GE-oos"), while Servo pronounces it correctly as "GAH-ohs". This turns into a small Running Gag throughout the rest of the episode with Joel occasionally mispronouncing it and having Servo correct him immediately afterwards.
Running Gag: Joel and Servo name off some things that Gaos' head could be used for, like a ski slope or an ironing board.
There are quite a few jokes about the grandfather being a cow.
After Servo gets his Mighty Voice, he'll occasionally finish off what he's saying by announcing his full name.
Vocal Evolution: One of the host segments has Joel changing Servo's voice from his vaguely Kermit-like one to the Mighty voice that Weinstein used throughout the rest of his time as Servo.