A doofnoob is someone that is such a bigdoofus and such a Noob that even Noob is not a strong enough word to describe how much of a novice the person is.
Tony: "Dude I just got spawn trapped to death and I died 10 times in 2 minutes!"
A mystical creature that dwells in the cave of Goobatopia, and plays and organ in the spotlight of his cave while wearing a cape and screaming "I'm a goofy gooba."