Prevents opposing Pokémon from fleeing.
Arena Trap is an ability introduced in Generation III. So far, 2 Pokémon have this ability.
Prevents all foes from fleeing or switching out as long as the bearer remains in battle. Pokémon rendered immune to Ground type attacks (via type or ability), as well as Ghost-type Pokémon, are immune to Arena Trap. Using Baton Pass, U-Turn, or Volt Switch will still allow the Pokémon to switch out. Having the Ability Run Away or holding a Smoke Ball allows the Pokémon to flee, but not switch. In this sense, it can be considered a Ground counterpart to Shadow Tag.
Outside of battle
If a Pokémon with Arena Trap is the leading party Pokémon, wild Pokémon are twice as likely to appear.
Pokémon with Arena Trap