Monster that bestowed grafts source.

[Smegskull]

I remember there being a creature that would eat players and then spit them out modified with a graft randomly selected from a table, it was a construct of some sort i think. Does anyone remember it's name or what book it is from?

[Zaq]

You're not thinking of the sibriex from Fiendish Codex 1, are you? Or else maybe one of the weird artifact things in BoVD?

[daremetoidareyo]

Silthilar from lords of madness?

[TheCount]

Fiendish codex 2 had that,away from book though.
I think it's a some kind of forge iirc.
And it gives its own grafts.... Or was that a disease?.

[Noxangelo]

Book of vile darkness

[Feantar]

I think that, in the BoVD, there's an infernal machine - or something to that effect. Not a monster exactly. The afformentioned Sibriex gives free fiendish grafts, but they don't have to be random.

[ShurikVch]

If non-random is OK, then, in the Fiend Folio, Yuan-Ti Anathema can grant Yuan-Ti grafts (up to 8/day), and Fiend of Corruption PrC - fiendish graft or symbiont (1/month)