Aquatic Swimmer Also Known as a Puffer
Puzzle 20 of Solving a Mystery Easy Pack
Question is: Aquatic Swimmer Also Known as a Puffer
and the answer is: BLOWFISH
Word Meaning:
BLOWFISH — Any species of fish of the family Tetraodontidae that have the ability to inflate themselves to a globe several times their normal size by swallowing water or air when threatened.
Definitions from Wiktionary.