Peekaboo

Peekaboo is a virus appearing in the Mega Man Star Force series. They look like large grey ghosts with their hands covering their faces. When they do show their face, it lets out a sonic wave, the "Ghost Pulse". They also have faces on their hands, but these hands are much happier than the actual face. When Peekaboo reveals his mouth, a small cannon can be seen.

Another version is the Wavyboo.

HP: 100 Wavyboo HP: 130