What's the Catch? is an achievement in Plants vs. Zombies: Garden Warfare 2. To get it, the player must give five of their stars to the Mysterious Fish, who will then train the player and give them XP.
The achievement name is a pun on the phrase "What's the catch?" used when a deal is suspiciously sided against the proposer to make sure it's not a trick, and catch as in what a fisherman has caught.