Augustus the bear is a card-board-cutout bear who was a prominent character in JackSucksAtLife media for a very long time. He has been referred to by Jack as his roommate and friend in the past.
Augustus appears to have been introduced before Cleopatra, likely making him the eldest of the two bears on the channel.
Augustus was removed from the background predating Jack's move by nearly a year along with Cleopatra, meaning it has been nearly 5 years since he has been no longer prominent. He has been in the attic ever since.