Viper (played by David Lipper) is a recurring character during season eight. He is an ex-boyfriend of D.J.'s, and he played in Jesse's band called Hot Daddy and the Monkey Puppets.
D.J. and Viper first meet when Jesse holds auditions for guitarists for his new band. They immediately hit it off, and begin to date, much to the chagrin of Jesse, who sees a little too much of himself in the young and wild Viper (who even has a cobra tattooed on his arm), and especially Danny, who was convinced that he is nothing more than a wild, uncontrollable, long-haired rock-and-roll "animal". Eventually, both Jesse and Danny learn to accept him for the kind and gentle person that he truly is on the inside, and he and D.J. continue to date. His last appearance is in the episode "D.J.'s Choice", in which he breaks up with her, only to want her back a few days later. He then finds out that she has resumed dating Nelson. At the end of the episode, he and Nelson are so busy competing with each other to try to "win" her that she decides she doesn't want to date either of them.