Let's come up with an amphibian race!

1 Triton - Agile Triton (attack increases with population growth - dodges attacks due to agility).
2 Turtle - Giant Turtle (can avoid damage by retracting into its shell).
3 Spider - Sea Spider (poisonous shot, ensnares - ensnares from a distance).
4 Crocodile - Alligator-Killer (main weapon - teeth, has a chance to bite in half, reducing the enemy unit by half).
5 Neptune - Neptune Hunter (throws a trident, casts a random spell).
6 Kraken - King of Octopuses (attacks everyone, ensnares).
7 Something - Mystery of the Sea (teleports, after death becomes a whirlpool that sucks in everyone nearby).