Megabyte is a power-hungry virus with ambition to boot. He is dignified, however, and always wants to make a good impression, even when he is trying to infect the super computer.

Megabyte is known all over Mainframe for his reputable fights with his sister, Hexadecimal. The pair were created in the same explosion, and each got specific attributes: Hexadecimal got strong, chaotic power. Megabyte got brawn and a calculating thought-process. He is constantly trying to take over something, whether it be the Principal Office, Mainframe, or the super computer.

Bob is Megabyte's greatest rival because he is always foiling his diabolical plans. Megabyte does not tolerate being made to look like a fool, but when Bob is around, this always seems to happen. Because of this, Megabyte holds a special loathing for Bob, and spends many of his days trying to make Bob's life miserable.

His plans backfire when he is sent to the Web at the end of Season Three, but is back with a vengence in Season Four, having transformed into a degraded Trojan Horse virus. He is more dangerous than ever in this state because he can adopt the attributes of any person he wishes - even Bob. He will never stop until he has gotten his revenge, or until he is deleted trying.

Megabyte adds pure evil to ReBoot, and his existence provides a reason for the Mainframers to fight for their honour. He is a strong, cunning, character who likes to keep his dignity no matter what. He is a powerful match for Bob and his friends.