Wild Tank

Wild Tank (ワイルドタンク) is a Mechaniloid enemy from Mega Man X3 that appears only in Neon Tiger's stage. It appears to have an unused behavior where it would dig up to the ground when you came near it, however in the final game all Wild Tanks appear above ground.

Other Media
A Wild Tank is among the Maverick minions catching X while he was fighting Crush Crawfish in the Rockman X3 manga. Another one is later seen fighting Neon Tiger, Blast Hornet, Blizzard Buffalo, Tunnel Rhino, and Volt Catfish.