This isn't the kind you get in Christmas crackers. This is an Anglo Saxon riddle from the Book of Exeter. The book does not provide an answer, but there is a scholarly consensus on what the answer is. That is the answer I will accept.
Ic eom mare þonne þes mindan geard,
læsse þonne hond wyrm, leohtre þonne mona,
swiftre þonne sunne. Sæs me sind ealle
flodas on fæðmum ond þas foldan bearm,
aregrene wongas. Grundum ic hrine,
helle underhnige, heofonas oferstige,
wuldres eþel, wide ræce
ofer engla eard; eorþan gefylle,
ealne middangeard ond merestreamas
side mid me sylfum. Saga hwæt ic hatte.
I am greater than this middle yard,
less than a hand worm, brighter than the moon,
quicker than the sun. All of the oceans, the flooding,
are in my embrace and in my bosom
green meadows. I touch at the ground,
deep beneath the hell, rise far above heaven,
and to the glorious homeland I reach out
over the yard, to fill the earth,
all of the middle world and the ocean roads,
wide, by myself. Say my name.