Chum Bucket

The Chum Bucket is a consumable which increases fishing power when thrown into a liquid. It is dropped with a chance from Blood Moon enemies: the Wandering Eye Fish and Zombie Merman drop it in stacks of 4–6, and the Hemogoblin Shark, Blood Eel, and Dreadnautilus in stacks of 7–10. These enemies spawn when fishing during a Blood Moon.

The fishing power bonus depends on how many chum buckets are present on the water's surface. A single bucket used will increase fishing power by 11(4%), two for 17 (2%) and finally three for a max bonus of 20(7%). This bonus is added after all other fishing factors and so isn't influenced by time factors like other fishing gear are. It also seems to hugely increase the chance of fishing enemies during a Blood Moon though this may be because of the fishing skill increase.

Each bucket lasts up to 10 times reeling in the line, even if nothing is on the line or if the line breaks. Certainly the use of a Sonar Potion is advisable.

Trivia

 * The tooltip is a reference to the popular kids show Spongebob Squarepants. Plankton, the main antagonist of the series, owns a bucket-shaped restaurant which shares the name of this item. Additionally, he exclusively sells chum from there.
 * Chum buckets in real life are used by fishermen to lure sharks.