LarkMan.EXE

LarkMan.EXE, known as SwallowMan.EXE (スワローマン) in Japan, is a NetNavi that appears as an optional boss in MegaMan Battle Network 5 (in UnderNet 1). He is referenced on the SciLab BBS as a "cyber-lark" that someone saw flying into the UnderNet. The discussion then starts to be about the UnderNet rather than Larkman himself, though.

MegaMan Battle Network 5
He is an optional boss found in the UnderNet. He considers himself the freest of birds and doesn't have an operater. You can fight him for the LarkMan chips.

MegaMan NT Warrior
He appears in Stream as a Darkloid.