From Cartoon Network I think.
Characters are a dog and an alien creature. Don’t remember just how it begins, but the two are in some sort of contest that keeps escalating.
At one point they’re playing electric guitars. Then there’s a Roman chariot race scene where the dog is on some sort of scooter and the alien is on a tricked out chopper trike.
Final scene is the alien walking up behind the dog and just swallowing it whole.
Bonus points for link to video. 
It’s not Prometheus and Bob, is it? But then, that was an alien and a caveman. And it was claymation. Grr. I suck.
ETA: Courage the Cowardly Dog? It was on Cartoon Network and it was pretty bizarre.
Sure sounds like Courage, although the specific plot isn’t ringing a bell for me. Courage was weeeeeird.
Wasn’t a series. May have just been a 15 minute short.
The dog was bipedal, kind of built along the lines of Marvin the Martian’s dog K-9 when it’s walking upright.
Kinda fuzzy on the alien. Shorter and with a puffball on a stalk on top of it’s head IIRC.
Hmmm. I’m stuck now. But I’m really curious myself now. Do you think it was one of the What a Cartoon shorts that didn’t make it to a full length series?
Something from Invader Zim?
I agree, it sounds like Courage, but I can’t think of a particular episode that matched that description.
Or, as a long shot, how about Moxy and Flea?
Did the dog look like this? If so, then yeah, it was Courage. Otherwise I got nuthin’.
Perfect!
That was just the clue I needed to refine my search.
Got me to the Cartoon Cartoon Show listings where I found Shake and Flick:Raw deal in Rome.
It seems that the ‘alien’ is really a flea. Umm? Really? Anybody watch that and think flea?
And the previously mentioned puffball on a stalk is the dog’s hairdo. My mistake. Too much alcohol since that was aired. Forgive me.
The reason I’m trying to find it is that ever since I first saw it I thought it would be too cool to have a motorcycle like the one appearing at 5:40. And now that I have the shop space and tools…
Thanks everyone!
It definitely doesn’t look flea-like, but then I guess not many cartoon insects can get away with looking like insects and still being cute.
