In Which Wurmple's Which?, May argued with Jessie over which one of them had the better Wurmple. After Max concluded that the two Wurmple are exactly the same, they began battling, but Team Rocket was sent blasting off by Pikachu. May soon realized that she has Jessie's Wurmple and that Jessie has hers. While with Team Rocket, Wurmple caused trouble for them by eating what little food they had, proving to be far more gluttonous than Jessie's Wurmple. Eventually, Wurmple was handed back to May in exchange for Jessie's Wurmple.
In Seeing is Believing!, Silcoon once again battled Cascoon in an attempt to prove to Jessie that her Pokémon was not a Silcoon, evolving into Beautifly in the process. Later on, Cascoon evolved as well and the two once again fought, with Beautifly winning.
Later, in Come What May!, Beautifly entered the Fallarbor Town Contest, where it impressed the judges in the Appeal Round. In the second round, it went up against Jessie's Dustox. It initially struggled, but was able to win by dealing a variety of damage to Dustox, which caused the rainbow device on her bow tie to break, revealing her as a cheater. In the final round, Beautifly battled Grace and her Medicham. After a hard fought battle, Beautifly was declared the victor, earning May her first Ribbon.
Beautifly and Bulbasaur in the Hoenn Grand Festival
In That's Just Swellow, May used Beautifly in the Crossgate PokéRinger. James, using Dustox, took advantage of Beautifly's own attack to quickly win their round, riding the attack to quickly score and knocking May out of the competition.
As a Wurmple, it would gorge itself on food and then fall asleep, unlike Jessie's more sedate and well-behaved Wurmple. It also had a remarkably lazy personality. When it evolved into Silcoon and then Beautifly, however, it became more calm and mellow. As a Beautifly, it often likes to sit atop May's head, and it appears to only do so to those it considers her friends, such as when it landed on top of Ash's head after it and May came to Sinnoh. She also frequently used it alongside Ash's Swellow to look for Team Rocket whenever they got away with something.