Limber

Introduced in Generation III, Limber provides complete immunity to paralysis. The Pokemon cannot be paralyzed by any means -- whether through dedicated status moves like Thunder Wave and Stun Spore, secondary effects of attacks like Body Slam or Thunderbolt, or contact-triggered abilities like Static.

If the Pokemon somehow becomes paralyzed and then acquires Limber through Skill Swap or a similar effect, the paralysis is immediately cured. This healing also applies when a Pokemon regains its original Limber ability upon leaving battle after having it suppressed or replaced during combat.

Found on 14 Pokemon including Persian, Hitmonlee, Ditto, Hawlucha, and the Buneary line, Limber is a straightforward but reliable defensive ability that guarantees the user will never suffer the speed halving and movement restriction that paralysis imposes.