|Portrayed by:||Grant Shaud|
|Only Appearance:||Make 'Em Laugh|
Harry Loomis was transformed into the Pack Rat by a disgruntled Joker.
Loomis was a known Gotham comedian. With Lisa Lorraine and Buddy Standler, he served as judge at the annual Laff-Off comedy competition. One year, an unregistered contestant was given the hook. That contestant, actually the Joker in disguise, swore revenge, and with Mad Hatter's mind control technology, humiliated all three judges.
Under the Joker's control, Loomis was transformed into the Pack Rat, a scurrying thief who cared only about packages, casings and other trash. The Pack Rat held up Mayfields, taking loads of trash. Alfred, who happened to be shopping there, managed to alert Batman. Pack Rat caught him, and rounded up all the staff and customers.
It wasn't long before Batman arrived and constrict Pack Rat with a bola, but failed to disarm him. Trapped, Pack Rat fired off his automatic gun. In a hail of bullets, Batman and Robin jumped away, and Pack Rat was able to free himself. He went after Batman, who had snuck up behind him and punched him. Now disarmed, Pack Rat grabbed a golf club, but he was stunned when he hit an electrical wire.