Sea Attacker

Sea Attacker (シーアタッカー) is a seahorse Mechaniloid that appears in Launch Octopus's stage in Mega Man X and Mega Man Xtreme 2. They shoot up from below (bubbles indicate that they'll appear) and after being stationary for a moment, they roll up and speed toward X. From Mega Man Maverick Hunter X they also appear in the first Sigma Palace stage right before X faces Launch Octopus. They aren't very strong, causing little damage and going down with few hits. They come in packs of three, and they usually launch themselves out of spike pits, though they can surprisingly rise from regular terrain.

Sea Attacker ST
Sea Attacker ST is a modified Sea Attacker from Mega Man X6 that appears in Rainy Turtloid's stage. They can curl into a spiked ball and launch themselves at X or Zero.

Other media
Sea Attackers appeared in the Rockman X manga.