The Pokémon anime's version of Misty was on a quest to be a master of Water-type Pokémon, which meant she had to be pretty good at fishing to even encounter most of them. It turns out that Misty has had a special trick to help her in her fishing, and that trick is so good it managed to land one trainer who used it a Legendary Pokémon.
Since Misty started out as a Gym Leader, she already had several Water-type Pokémon to begin with, including Staryu and Starmie. She also caught several of them on her journey with Ash, like Corsola, Horsea, and Politoed. Misty has tried throughout the Pokémon anime to fish for Water-type Pokémon, and although none of her main team were acquired that way, she was successful at it. Her secret is a special lure--one that looks like a chibi version of herself.
Misty's Lure First Debuted in a Banned Pokémon Episode
Misty's lure first appears in the banned episode "The Legend of Dratini," wherein she uses it (and a box of other Pokémon-shaped lures), to Ash's amusement and derision. Since that episode never aired in the US, the first time most American fans saw it was in the Pokémon Orange Islands episode "Bye Bye, Psyduck," when Misty pulled it out to compare with another Water-type trainer's own lures. This one looks a bit different from the first, and more closely resembles a traditional fishing lure. She uses it again in the Johto episode "The Totodile Duel," where she tries to fish for a Totodile, and one last time in "Hook, Line, and Stinker," where she successfully wins a fishing contest with the largest Seaking, caught by using her lure. Ash is initially quite dismissive of Misty's lure, but after seeing its success, changes his tune. Misty eventually sends him one of her lures after leaving the series and shares another with Lana, a fellow Water-type trainer from Sun & Moon.
Misty Lure Can Catch Legendary Pokémon Like Kyogre
Misty's lure would go on to be a lucky charm for both Ash and Lana. Ash used it in the Sinnoh episode "Buizel Your Way Out of This!", wherein he had a small argument with Dawn over using it before casting it out. This ultimately leads to the rod and lure being stolen by a Buizel, which Dawn eventually catches. Lana and Misty first bonded over being Water-type trainers when Misty had her guest appearance during Pokémon Sun & Moon. At some point, Misty gave Lana the latest version of her lure, this one depicting chibi Misty in a swimsuit. In "The One That Didn't Get Away!", Lana uses this lure, soaked in Antidote, to fish out a Kyogre that was being harassed by a poacher. The poacher had poisoned Kyogre, and Lana was attempting to help it. While it took a few tries, Kyogre did eventually bite the Misty lure and was healed of its poison, giving it the strength to fight off the poachers. Given the situation, Lana did not attempt to capture the Kyogre, and instead released it back into the sea.
Misty's lures may seem dubious, but there's no denying that it managed to pull in a Legendary Pokémon that would make any Water-type trainer beam with pride. One can't help but wonder how Misty must've felt when she finally heard this story!