Boomer, known as Rounder (ラウンダ,Raunda?) in Japan, is a virus from the Mega Man Battle Network series. It attacks by shooting a boomerang that travels along the outer walls of the field. It hits every panel except for those in the middle. It is invulnerable until it releases its boomerang as part of its attack, at the end of which it catches the boomerang and is once again invulnerable. Stronger variants of this virus utilize PanelGrab chips, stealing the center panel.
Boomer is a black and purple variant with red eyes and a silver blade.
Gloomer (ラウンダラウ) is a green and blue variant with orange eyes and a silver blade.
Doomer (ラウンダバー) is a purple and green variant with yellow eyes and a gold blade.
BoomerΩ is a blue and light-blue variant with orange eyes and a silver blade.
BoomerEX is a red and gray variant with blue eyes and a silver blade.
GloomerEX is a silver and dark-gray variant with orange eyes and a gold-silver blade.