Lance's Petilil is the first Pokémon that Lance catches once starting his journey.
Petilil is very prideful and vain, caring little for Lance until he shields the Pokémon from a stray Tranquil causing it to warm up to him to the point of seeming to harbor a crush (in a similar manner to Ash's Chikorita in the Pokémon anime) and becomes the first to jump into battle whenever the chance arises.
After evolving its apparent crush on Lance's lessens, and it instead starts seeing its trainer as something similar to an older brother or father figure. Of note is its tendency to use its Energy Ball on him if it thinks he is slacking off to much.
- Petilil is the first of Lance's Pokémon to evolve to its final stage.
- At one point Lance says he only caught Petilil because "Elesa posed with a Lilligant once".
- Petilil is the only of Lance's Pokémon to have its ability, Own Tempo, directly revealed when it is uneffected by a Tympole's Super Sonic.
- Petilil is the only of Lance's Pokémon to have a nickname.
- It is also the only Pokémon given a nickname by someone other than its trainer.