Monitor lizard is a fictional animal character in the Hey Arnold! TV Series.
It was purchased at Pet's Love by Helga as an excuse for her being at the pet shop when Arnold sees her there. She gave the lizard to Phoebe to hold on to, but her parents would not allow to keep it. This resulting in Phoebe bringing it to school for Helga to retrieve where it ended up getting loose from its leash and eating Helga's Parrot. Helga then accepts the lizard as her pet by petting it under its chin with one finger saying they were going to get along just fine as the lizard smiles with loyalty for its owner. During Mr. Simmons's term as principal at P.S. 118, the monitor lizard was seen dragging Eugene down the school hallway. These are the only episodes Helga's pet monitor lizard appeared in.
- It is possible that this Monitor Lizard is a Nile Monitor or more likely a Lace Monitor, however there are no real life monitor lizards that have the same coloring as the monitor lizard in the show, making it unknown what kind of monitor lizard it is.
- The Monitor Lizard only appeared in the episodes Helga's Parrot and Principal Simmons. It's not even seen at Helga's house, despite her deciding to keep it and the lizard seeming to take a liking to Helga at the end of the episode Helga's Parrot. It's possible Helga's parents made her get rid of it, though they usually don't care about what she does or pay attention, so they could've been indifferent to Helga's keeping it for a pet. If she kept it, it's possible she kept it in a room where it wouldn't destroy anything in the house, especially anything of her, particularly her Arnold related items.
- The Monitor Lizard only smiles two times in the episode Helga's Parrot, as it usually frowns, much like how his owner usually appears when she's around others. The two times the lizard smiled were when it ate the parrot and when Helga pets under its chin with one finger. When Helga embraces the lizard, it's the only time it smiles without a frown, since its smile had a devious satisfaction to it from catching its prey. It only gave a genuinely friendly smile when Helga embraces it, showing that it had taken a liking to Helga and agreed with her that they'd get along just fine.
- It's often said that owners look like their dogs, which could apply with Helga and her lizard to an extent. The lizard is usually seen with a frown on its face, much like Helga does when she's around other people. One of the few times it smiled was in a devious way (from eating the unsuspecting parrot) like how Helga does with pranks that are caused by her and others to her peers. It only genuinely smiled in a friendly way when Helga gave it loving attention, like how Helga usually smiles with genuine happiness when it involves Arnold, so both give genuine smiles when involving someone they have affection for. Although other than that, there isn't any other resemblances between them.