Encouragement to Pull on a Rope, as in Tug-of-War

Puzzle 19 of Animals with Weird Names Hard Pack

Question is: Encouragement to Pull on a Rope, as in Tug-of-War

and the answer is: HEAVEHO

Word Meaning:

HEAVE — (transitive) To lift with difficulty; to raise with some effort; to lift (a heavy thing).

Definitions from Wiktionary.