Back in Generation 2 of pokemon, Leer (A Defence Debuff) looked like lasers coming out of the pokemon's eyes. It's one of the first few moves Totodile learns when you select him from the start of the game. In Twitch Plays Pokemon, since there are over fifty thousand players trying to take control of the actions of the hero, more often than not there are a lot of mistakes. Like constantly spamming Leer.
So the Mob (What most people call the 50000+ people on Twitch Plays Pokemon also abbreviated TPP) named the totodile "Lasergator" and "King Leer" for constantly using Leer, which looks like lasers shooting out of Totodile's eyes.
This name doesn't really apply much anymore at the time of writing however, as the epitomize "Lasergator" no longer has Leer, though it's still used in events such as now, which showcases totodile's time as King Leer.
