D&D 30-day Challenge - Day 18: Favorite Outsider

I think my favorite outsider is the Hound Archon. I like the idea of a celestial paladin with the attributes of a loyal and protective dog. I seem to recall at one point one of my friends rolled up one as a PC. I'm pretty sure he played him some, but I don't recall the details. I think it might have been in TWLD again (a lot of stuff happened in there). Anyways, I did a picture of him, and it turned out pretty neat (not the one to the left, obviously).

As a DM, I'd love to get the chance to use one. Probably as a stray dog, or a lone wolf who starts following the party of its own accord, and latches on to one of the PC's. How awesome would that reveal be when they face a demon?