– “Nano of the North”, The Powerpuff Girls (4×08)
(Allusion: Guess who voices a pony in the future?)
No one seems to have noticed that this is Pony Puff Princess, the show-within-a-show that was also in Dexter’s Laboratory
Which in turn was a reference to the general girly pony things of that time, mainly My Little Pony plastic horses with combable manes.
There are many allusions from GT’s work on Craig McCracken’s.