Upon appearing for the player, he cycles randomly through a number of different phrases. He will eventually disappear and can be summoned again in the same way.
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He is a reference to Mod Osborne dressed up as an elf in the "Road to Prifddinas" Behind the Scenes videos. His examine text references Osborne's reputation for having a large face, as well as being known as "the face of RuneScape" according to an interview from RuneFest 2013.
"Goblins are just elves that have shrunk in the wash!" is a reference to J.R.R. Tolkien's books. Orcs and Goblins are believed to have evolved from Elves when Melkor (later Morgoth) captured, corrupted and bred them.
When trying to re-summon him, there used to be the message "Mod Elfborne's appetite has already been sated, he will not return again."
The abyssal demonGrapefruit sometimes references Mod Elfborne by saying "Ellllfff...." or "...booorne..." as it wanders around.