"Main Theme - Hooked" is a high quality rip of "Main Theme" from Hooked.
This rip parodies the Hooked ad, seen on Youtube. The music that's playing is in the tune of Meet the Flintstones. In the background, there is a robot-looking Grand Dad. As well, a conversation, like the ones in the ads, is going on:
Jeff: GRAND DAD
Joel: Who...is this?
Joel: Why do you have my phone number?
Joel: No really, who are you? You're freaking me out right now.
Jeff: WHAT THE SHIT?!?!
Joel: I'm done. Fuck you and your shitty meme, it's not funny anymore.
Jeff: AAAAAAAAAAAAAAWhen Jeff texts "AAAAAAAAAAAAAA", it plays a Loud Nigra scream, and the robotic Grand Dad comes forward. Near the end, we see the text "Please read the channel description", instead of "Install Hooked to read more".