Piranha

Piranha are viruses from Mega Man Battle Network and Mega Man Battle Network 6 games. These viruses have a fish-like design. When in battle, Piranhas move up and down the column in which they are located. Their arms are constantly rotating in a propeller-like fashion. When they first move to a panel, they release a lock-on cross-hair traveling forward into the players direction. If there are no obstacles in the way of the traveling cross-hair, then the virus moves onto the next panel and repeats the attacking process. If the cross-hair lands on the player, it will quickly attempt to lock-on and begin shooting metallic arrows from its mouth at them. The player can move away, even if they are locked onto, to successfully avoid the attack.

Piranha
Piranha have green-colored scales and orange-colored fins. Their arms and face is of greyish tone.

Piranha2
Piranha2  have red-colored scales and yellow-colored fins. Their arms and face is of pale-pink tone.

Piranha3
Piranha3  have blue-colored scales and green-colored fins. Their arms and face is of light-bluish tone.

PiranhaSP
PiranhaSP  have grey-colored scales and pink-colored fins. Their arms and face is of light-purple tone.

RarePiranha
RarePiranha  have pink-colored scales and blue-colored fins. Their arms and face is of greenish tone.

RarePiranha2
RarePiranha2  have yellow-colored scales and grey-colored fins. Their arms and face is of yellow tone.

Trivia

 * Piranha and Handy viruses are the only viruses to ever reappear after their blacked-out chip image status, unlike viruses such as Minelayer, Mollusk, and Fanner, that appear only in the first game, and never show up again, resulting in a permanently blacked-out chips in the subsequent games.