Most Grumpy, or Most Like a Shelled Beach Creature

This page is the CodyCross answer for the clue below from The 1950s, Group 1820, Puzzle 2 (Milkshakes).

Question is: Most Grumpy, or Most Like a Shelled Beach Creature

and the answer is: CRABBIEST

Word Meaning:

CRABBIEST — superlative form of crabby: most crabby

Definitions from Wiktionary.