A Berry to be consumed by Pokémon. If a Pokémon holds one, its critical-hit ratio will increase when it's in a pinch.
Sharply raises critical hit ratio when HP is below ¼.
You can get a Lansat berry at Battle Maison Lobby by the a girl after you break 100 wins in a row and a Starf berry in 200.
Source
Hope this helps.
