Chum

Chums are a type of Salmonid, the main antagonists of Salmon Run in Splatoon 2. Chums are the most common form of Salmonid, and use a frying pan to attack Inklings. They are not very tough individually, but they can pose a threat in large numbers or against Inklings that aren't paying attention to their surroundings. During a Rush Chums become very fast and deadly, and they come in huge numbers.

Salmonid Field Guide
The following text is quoted from the Salmonid Field Guide.
 * Basic Information
 * They tend to appear in groups rather than alone.
 * Defeating them will earn you Power Eggs.
 * Attack Behavior
 * They use their sense of smell to locate and close in on targets who have entered their territory.
 * Once they close in on a target, they perform close-range attacks using frying pans or other cookware.
 * Elimination
 * Can be neutralized relatively easily with a direct hit of ink.
 * Supporting Information
 * They inhabit a restricted ocean zone, and any unauthorized contact with them is expressly forbidden by law.
 * On their own, they don't pose a significant threat, but ignore them and you may quickly find yourself surrounded.

Etymology
Chum is a type of meat that fishers use to attract sharks, and is also a species of salmon.