In the webcomic Dudley's dungeon, Dogley is sometimes the name of Dudley's pet dog. The name Fido is more common, while the name Slasher appeared once. The name "Dogley" seems to be a mix of "Dudley" and "dog" (possibly influenced by Dilbert's dog, Dogbert). Dogley named the Dogley Dimension after itself.
The difference between Fido and Dogley is that Fido is stupid, like a normal dog, while Dogley is intelligent and has his own personality.
Like any typical pet dog, Dogley is more capable of killing monsters than Dudley. (It is a common strategy in NetHack to let your starting pet kill the more difficult monsters. We like our pets, and would never eat or sacrifice their corpses! You miss a lot if you choose to start NetHack without a pet.) Thus pet dogs have delayed Dudley's death many times. Dogley is constantly turning into dragons, due to polymorph. The dragon-Dogley has saved Dudley many times.