Large Beast, Unaligned
Traits
Water Breathing. The seahorse can breathe only underwater.
Actions
Ram. Melee Attack Roll: +4, reach 5 ft. Hit: 9 (2d6 + 2) Bludgeoning damage, or 11 (2d8 + 2) Bludgeoning damage if the seahorse moved 20+ feet straight toward the target immediately before the hit.
Bonus Actions
Bubble Dash. While underwater, the seahorse moves up to half its Swim Speed without provoking Opportunity Attacks.
Found on p.359 of MM2025 (Free Rules)