Poppy's hammer

So it's probably too early to speculate (but who cares? Let's do it!) but has anyone wondered about the origins of Poppy's hammer?

It can't have been forged by Yordles. It is too big for them to use normally (I mean that it doesn't seem to be made with Yordles in mind). And it seems to belong to a destiny of some sort, thus implying it is very old.

I have three takes on it. The first being a runic weapon from Targon. Though the only runic weapons we know are Pantheons spear and shield. I don't know if Leona and Diana's are runic weapons (they are passed down though) because I tend to see them like Illaoi's sphere: they help channel their power.

Runic weapons are innately magical. This isn't shown through Pantheon outside of his spear never missing. But this hammer summons hammers from the ground! So maybe it's an ancient runic weapon.

The second idea is that it's older than Mordekaiser. Possibly having a hand in his defeat. Though I haven't thought into this one yet.

Finally, could it be a weapon from the blessed isles? This is probably a much bigger stretch, but I think it's worth considering.

Thoughts? Any theories to share?