1 Triton - Agile Triton (attack increases with numbers - dodges thanks to agility)
2 Turtle - Giant Turtle (can avoid damage when 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 (teleport, after death becomes a whirlpool that sucks in everyone nearby).
Added 1 minute ago
The monster dwellings are also well done))
Added 2 minutes ago
Something like that. The hero is water-based. His abilities are something like this: Power of Water (additional damage with a water jet for the army) - Fluidity (allows units to pass through walls) - Water Wall (repels the enemy).