Tybalt is Martellus von Blitzengaard's second-in-command when Tweedle arrives at the Corbettite Depot Fortress at the head of an army in pursuit of both Agatha Heterodyne and Margarella Selnikov. Tybalt displays eager and enthusiastic loyalty to Tweedle, and is the one sent to officially ask for parley with the Corbettite Monks. He first appears to be a human wearing a copy of Professor Eg's Nerve-Enhancing Armor, but when forced to while rescuing Tweedle from the magnetic pull of The Beast, it is revealed he is actually a Sparkhound, or something very similar. He escapes the Beast by running away on his hind legs, carrying Tweedle under one arm.
He expresses a preference for the color red.