He even makes up a theme song for her during the following Q&A.
Assistant-verse Doctor's scene with Adventure-verse Rarity in episode 7. And then Pinkie Pie shows up and, well, they only way to describe their interaction is "meshing." The two are even doing the same bouncy dance in the background! Adventure-verse Twilight almost blows a gasket. ^_^
Adventure-verse Doctor (Clockwork) reading the end credits...
Ditzy: Um...Clockwork? Who're you talking to? Clockwork: I'm doing the end credits...doesn't your Doctor do that at the end of every episode? Ditzy: No, he usually just eats a lot of butter and passes out on the floor. Clockwork: ...oh.
Ditzy sings Clockwork an impromptu musical number about how he shouldn't be so grumpy all the time, with the lyrics meandering into how much she loves muffins. Afterward, when Clockwork tries to figure out where the music came from, Ditzy apparently has no memory of the song.
Ditzy and Adventures-verse Twilight doing impressions of their respective Doctors.
The April Fool's Day special, in which the Doctor and Ditzy have had their lives turned into a bad Scooby-Doo rip-off, with a cast that includes Ditzy's children, Dinky and Sparkler, the latter of whom is constantly hit on by Captain Jack Harness, and Sparky Sue, the Totally Radical alicorn daughter of Celestia and Discord. When Nightmare Moon unleashes her army of Nyan-Cats, the Doctor finally loses it and storms off the set.
The beginning of the "Isle of Flaputa" episode is Tick Tock and Derpy playing a card game...while dressed up in silly outfits. Derpy is dressed as a Paper Bag Wizard, while Tick Tock is dressed as a Tulip Paladin, including him having a flower on his head and wearing a pink cape.