Large Ocean Animals That Flap Their Fins to Move

This page is the CodyCross answer for the clue below from All Things Water, Group 1283, Puzzle 3 (Paddle Boarding).

Question is: Large Ocean Animals That Flap Their Fins to Move

and the answer is: MANTARAYS

Word Meaning:

MANTA RAYS — plural of manta ray

Definitions from Wiktionary.