Bait

Bait serves as ammunition for Fishing Poles. They are generally Critters, though 3 non-Critter bait items can be acquired by completing quests for the Angler NPC. Most Critters that are insects or mollusks can be used as bait. They must be caught with the Bug Net.

Bait items are not always consumed. A bait item in your inventory only has a chance be consumed you catch something, be it a fish or junk, with the chances of consumption being based on the particular item's bait power: Items with higher bait powers have a lower chance of being consumed during a catch. The Truffle Worm will not do anything if it isn't used in an ocean biome with a rod of sufficient power(in which case it would summon Duke Fishron); it cannot be used to catch any fishing items. If you do not have any bait in your inventory, you can still use a Fishing Pole, but you will be unable to catch anything.

Tips

 * Running through a Forest biome during the Rain is an good way to gather Worms for bait.
 * Cutting bushes you find in a Forest can spawn multiple Worms.

Trivia

 * The Truffle Worm's bait power of 666% is probably a reference to the biblical number "666", commonly associated with Satan.
 * The Master Bait's name is probably a play on the word "masturbate".