Goo Shaver

Goo Shaver, also known as Gel Shaver (ジェルシェイバー) in Japan, is what X gains from defeating Duff McWhalen. In normal fire, it sends out a small wave of gel on the floor and walls until it hits an enemy. Charged up, X launches a small row of ice blocks in front and behind him.

(Note about the categories, the game somewhat considers this both a water and an ice weapon, hence the reason of being in both.) 