Cloudy

Cloudy, known as Kumonpe (クモンペ) in Japan, is a cloud virus from the Mega Man Battle Network series. These viruses jump up and down from square to square in a random fashion (on their side only). They cannot be hurt while in the progress of their jump; only when they land or are about to jump. Their attack consists of summoning a raining raincloud moving back and forth over one column of panels. Stronger variants send out faster moving and longer lasting rainclouds which deal more damage.

Cloud Family
Below are the images from Mega Man Battle Network (left) and Mega Man Battle Network 2 (right).

Battle Chips
Cloud (クラウド), Cloudier (モアクラウド), and Cloudiest (モストクラウド), named Lil' Cloud, Medium Cloud and Big Cloud in the second game, are the Battle Chips from the Cloudy family.

Other media
Cloudy appeared in the MegaMan NT Warrior anime.