A hellhound is a mythical creature typically depicted as a dog that is on fire. They lack the ability to speak, however they are usually portrayed as sentient and have an understanding of language. They would therefore be capable of casting magic assuming it requires no words or complex hand motions. For example, the hellhound could use its paws to draw any required glyphs/runes for a spell in, say, sand on the beach. Therefore, under certain circumstances, a hot dog is a sand witch.