Here is the full list of all 21 Zombie Deathrace Feeding Frenzy achievements.
Player has over 5 rounds of starfish hitting at over 50%
Player has over 5 rounds of biting at over 50%
Player has killed 10 fish
Player has over 5 rounds of torpedoes hitting at over 50%
Player has won 15 rounds
Player has won a match
Player has won a round
Player has won 30 rounds
Player has won 10 matches
Player has 50 urchin hits
Player has won 50 matches
Player has won 100 matches
Player has killed 50 fish
Player has over 50 rounds of starfish hitting at over 50%
Player has over 50 rounds of torpedoes hitting at over 50%
Player has 1000 urchin hits
Player has over 50 rounds of biting at over 50%
Player has over 100 rounds of biting at over 50%
Player has killed 100 fish
Player has over 100 rounds of starfish hitting at over 50%
Player has over 100 rounds of torpedoes hitting at over 50%