The Rush Mammoo (ラシマンムー Rashi Manmū) is a giant mammoth-like boss Reaverbot in Mega Man Legends 2, and is a larger version of the Mammoo, with MegaMan Volnutt only coming up to its ankle/knee.
The Rush Mammoo is the guardian over Sera's seal on Forbidden Island. It attacks by shooting ice blocks from its trunk, creating a shockwave with a jump, charging forward, and shooting energy blasts from its belly.
Strategy[]

Rush Mammoo in-game.
The trunk and the body are separate targets. Destroying the trunk makes it more likely to use the energy blasts. It is best to keep close to it because the energy blasts that it fires zig-zag in unpredictable ways which can make dodging them confusing.