Shuckle

The Pokémon cannot be knocked out by a single hit as long as its HP is full. One-hit KO moves will also fail to knock it out.

If the Pokémon is holding a Berry to be eaten when its HP is low, it will instead eat the Berry when its HP drops to half or less.

Reverses any stat changes affecting the Pokémon so that attempts to boost its stats instead lower them—and attempts to lower its stats will boost them.