Seaick Brothers

Seaick Brothers (シーイックブラザー, Shīikku Burazā): The Seaick Brothers are a trio of submarine style Headders that combine onto Gosei Great to form Seaick Gosei Great. They are composed of Manta Headder (マンタヘッダー, Manta Heddā), Sawshark Headder (ソーシャークヘッダー, Sōshāku Heddā), and Hammershark Headder (ハンマーシャークヘッダー, Hanmā Shāku Heddā).

Manta Headder
MantaHeader is a manta ray mecha that's a member of the Seaick Brothers.

Hammershark Headder
Hammershark Headder is a hammerhead shark mecha that's a member of the Seaick Brothers.

Sawshark Headder
Sawshark Headder is a saw shark mecha that's part of the Seaick Brothers.