Okay, this sounds ridiculous, but I remember this movie from when I was a kid. It involved some human kids going into the forest at night and meeting up with these weird creatures - purple things with antlers and long noses, like anteaters standing on their hind legs. One of them was this really nerdy guy, I think his name was Arthur, and his dad was the bad guy that was going to destroy the forest or something. Arthur had a girlfriend who was also an anteater thing, and she and the humans helped him stop his father. Was this an actual movie or was I just a REALLY weird kid?

You aren't freaking out. Arthur is an actual critter, an aardvark, to be exact. I'm not sure if there was ever a movie made, however his show still airs on BOOM every once in a while.

I don't think that's it - I'm not talking about the Arthur cartoon by Marc Brown that's on PBS. This was a movie that aired I think on HBO or something, and the creatures were definitely aliens or something weird like that.

No, this is a different Arthur than the one on PBS.

It does air on the BOOM channel and this guy is an aardvark.

Would you happen to be talking about Fraggle Rock?

No - it was some weird obscure cartoon. I remember very clearly there was an English Sheepdog in it, and these purple things were under the thumb of the bad guy, and the main purple guy and his girlfriend had to stand up to him and defeat him. I think that it later became a TV series.

But I did hear today that the Zappa family is producing a Fraggle Rock movie!

You're referring to the series The Raccoons, which was a Canadian cartoon series. The specific episode you're recalling is probably one of their specials, maybe The Christmas Raccoons? http://toonview.tryhappy.net/christmasraccoons.html

The nerdy aardvark you remembered as Arthur is actually Cedric, and his dad is Cyril Sneer. The dog's name is Schaeffer. It's funny, because I was trying to figure this out too, and could only remember the aardvark-like characters, but not the raccoons, which were supposed to be the main characters!