This monster appears in the Dungeons & Dragons Player's Handbook 2024.
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 the seahorse deals 11 (2d8 + 2) Bludgeoning damage if it moved at least 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.