Tarak

Not entirely true... He can still drop items if he is drug out of the room.

I believe the connection between him not dropping anything is if he has gotten in any fights with any other sanctuary monsters, then he no longer drops anything. I am not sure if this is true or not. Or if he just doesnt drop anything sometimes because he doesnt have anything. That wouldnt surprise me at all, ive seen almost every boss drop nothing.

But I have seen him drop items outside of his temple.

edit...
Also watch out, not only does he summon, but he polys you into Zombies.

And to answer your question Tikie. Tarak is the Boss of Sanctuary Of Evil and he is located in the Demon Temple to the north.

MerryXmas/Elaine and crew do, or used to, all the time on Dep.