Facts (and speculation):

• He's a lefty and can draw with both left paws.
• Loves upbeat music; any genre will do.
• Loves to dance; often dances while walking down the street and accidentally bumps into things.
• His jacket originally only had one pair of sleeves. He sewed on the second pair from another jacket he bought at a thrift store.
• His favorite food is cheeseburgers with sriracha, and his favorite drink is raspberry punch.
• He is actually a spirit who materializes at sunrise every day and disappears at sunset, often by dancing in and out of a cloud of mist.
• He is 22 years old and has been for thousands of years.
• He can pop in and out of existence at any time.
• He never removes his earbuds. Never. They might as well be attached to his ears.
• He always has chalk dust on his paws. It can't be washed off. Don't worry, it's non-toxic.
• He never speaks. Instead, he communicates by magically changing the text on his shirt. He may make the usual dog noises such as barking, whimpering, and growling, though.
• He's a “live for the moment” kind of dog. He doesn't think about tomorrow, nor can he remember yesterday. He starts the day with a clean slate, and approaches it as if it's going to be the best day ever.
• Some say he has the personality (and the comic reality-bending abilities) of a 30s inkblot cartoon character.
• He treats just about everyone he meets as if they were a long-time friend, because he doesn't remember whether they really are or not.
• He's friendly, but can also be skittish, and will run away if he feels uncomfortable or threatened.
• He's an excellent escape artist. He can get lost in a crowd or run around a corner and completely vanish.
• He's been said to be able to draw things into existence, but this hasn't been proven.
• A few people think he might be an avatar of Shiva, the Hindu god of creation and destruction. One person actually asked him if he was. In response, Pow-Pow twirled around, stuck out his tongue, and his shirt read, “You're Silly!”