Virus Breeder

The Virus Breeder is a machine in MegaMan Battle Network 3, created with the intent of studying various virus species. During the game, Lan Hikari and MegaMan.EXE are asked to round up viruses and send them to the Virus Breeder as a side quest. While some viruses are gotten by different means, most are found when MegaMan walks onto a certain place on the net, resulting in a battle with all versions of that particular virus. When defeated, they will stand idle in front of MegaMan, where he sends them to the Virus Breeder. By returning to the breeder, Lan can receive a chip that summons that species of virus, cycling through the different versions before being summoned with the A button.

By Jacking In into the Virus Breeder, MegaMan can feed each species of virus a certain amount Bug Frags, which increases their attack power. However, because there are multiple versions of the same species, the Bug Frags must be distributed amongst them, leaving the player to decide which version should get the most, and in turn, which one does the most damage.

Once the game is beaten and certain requirements are met, the Ω version of each species and the Scuttle viruses can be obtained.