From the RuneScape Wiki, the wiki for all things RuneScape

Frederic Traiborn

Release date	Unknown edit
Race	Human
Members NPC?	No
Quest NPC?	Yes - Demon Slayer, Recipe for Disaster, Defender of Varrock
Location	Wizard's Tower second floor
Sells items?	No
Skill requirement?	No
Quest requirement?	No
Gender	Male
Examine	An old wizard.
Notable features	Crazy mage.

Frederic Traiborn is a strange wizard who resides on the first floor of the Wizard's Tower. He often addresses players as "thingummywut".

He is included in the quests Demon Slayer and Recipe for Disaster. During Demon Slayer, if asked, Traiborn will give you a spinach roll.

His first name was revealed by Jagex, along with the fact that he is "very sensitive about his first name and often does not tell others what it is"^[1].

He is in possession of a magic wardrobe, which he summons with 25 bones during Demon Slayer.

Wings of dark and colour too, Spreading in the morning dew; Locked away I have a key; Return it now, please, unto me.

— Traiborn

Traiborn indeed appears to possess more power than anyone, even the player, might suspect. He is described as "a strong magician" on his entry in the Jagex website, being key to the completion of two of the most famous and important RuneScape Quests as well as playing a minor part in Defender of Varrock, and having such magical proficiency that even the extraordinarily powerful and experienced Wise Old Man dares not as of yet launch his planned assault upon Wizards' Tower. The Wise Old Man even stated himself, in the 12th Postbag from the Hedge, that "the powers of Wizard Traiborn are not to be underestimated" and that thus he doubts he will make a move for "a considerable time."

Traiborn seems to be wearing a blue cape of legends but after the HD update he seems to be wearing a white and blue cape of legends.

References