Well, it's arguably not canonical, but here's one of the covers they did for the Adventure Time comic book (#8), if it helps. And it does for me. ^_^

But why have them fight when you can combine their cuteness? No mortal is safe from their sheer force of their adorableness! Bad guys beware!

A damn good episode - how can you not love a forest journey between BMO, LeVar Burton, & a giant baby? Or how can you not love BMO, period? - but I'm still hoping for that episode where we learn a bit about his backstory as well.

Of just the "I Fought The Slaw & The Slaw Won" Burger, kinda sounds better. Still, points for the perfect reference to use, bravo!

Yeah, I was disappointed when they didn't win as well. Or rather, I was disappointed that all the antagonists got a full Karma Houdini. I don't think I expected the Belchers to wind up with the minivan, but still being proven right about the game show cheating or maybe Jimmy's minivan getting wrecked somehow would…

"Oh and of course it's gonna recycle: this is TV, where money must be
made, and nothing is finite if it's successful."

"…but nothing can remain the greatest work Rabin cites in his recent My World of Flops."

The answer is all of the above, since calling those scenes "gags" kind of implies that they were actually funny.

"'I realized that, no matter what, you will never stop trying. And
there’s nothing a woman loves more than that.' A little meta, perhaps,
since it justifies infinitely more episodes with tonight’s plot."

You know, I just realized we totally missed an opportunity to suggest some Jem here. God I would kill to see The AV Club actually try th train wreck that was Jem. A damn good train wreck, mind you…like a glitter train colliding with a fireworks train. Also, holograms are involved. And a yeti. Good times…

Holy crap, "Lucy Goes to Scotland" made it?? Even I'm surprised by that, & I'M the one who suggested it!

While I've got to agree that Axl was a jerk, his behavior almost seems justified when Sue led to his band almost being renamed to "DaSeanAx". Really, Sue? That's not the name of a rock band, that's the name of a third-rate mid-'90s R&B band.

Wait, how did we go this far without suggesting any Chuck episode featuring Jeffster? "Chuck Versus the Ring", anyone? We should feel ashamed…

This. Cover this, please.

Hmm, good point…

What about "School Pageant" form Moral Orel? "I hate you Jesus, you rotten little fink…"

Wait, it just needs a musical number, not a musical episode? Oh, well screw that episode, then. I suggest either "Ethel's Home Town", "The Operetta", "Lucy and the Dummy", etc. Though "Scotland" is probably one of the few where it's not a job in any way…

Despite not being one of my favorite episodes, the fact that I've been watching constant reruns of it recently says that I may as well throw in I Love Lucy's "Lucy Goes to Scotland" episode. The Brigadoon-inspired musical episode where Lucy is sacrificed to a two-headed dragon, if that helps…

Thirded.

According to the Adventure Time Wiki, yep, that was indeed CMO…for those of you wondering (or too lazy to look it up), CMO is apparently from an episode exploring BMO's backstory, which was either scrapped or still in development (it also would've featured AMO, which is apparently the size of a Death Star).