This site has not yet been updated to reflect the changes in Reborn v19.5. It still only reflects the state of the game as of v19.16.
When the Pokémon uses Surf or Dive, it will come back with prey. When it takes damage, it will spit out the prey to attack.
There are no Pokémon with this ability. (It's probably a Gen 8 ability that's snuck its way into the database by mistake.)