Mini Zapfish are presumably baby Zapfish that have the same features as a regular Zapfish but are smaller, have a greenish tint, and have 1 whisker at the top of their head. In some levels, 8 of them are found at the end of the level in Splatoon 2 and freeing all of them counts as beating the stage. In others, there’s only 1, which Agent 4 must free to beat the stage. They are found in containers resembling light bulbs.

Trivia

• Mini Zapfish are much smaller than normal Zapfish.
• 8 Mini Zapfish are equal to the power of 1 Zapfish.
• They only appear in Splatoon 2.