Along with, or apart from the Balrog, the most iconic "boss" monster from The Lord of the Rings: The Fellowship of the Ring, must be the Moria Cave Troll (see below, equipped with Hobbit hunting spear - be sure to pack your best "mithril" armour):
He certainly is a chunky piece of lead, this being long before the resin Fine Cast 'experimentation' (aka disaster) and more modern injection moulding techniques replaced all the old metal "large monsters" (see below, from another angle you can see what a good pose the figure is in):
I found it lying next to the Balrog and decided to slip it together and was pleasantly pleased at how well the pieces fitted. I toyed with the ideal of pinning the joints but (something I may well regret later) I used a bit of cheap to hold the pieces in place an d then applied a good quality superglue. It seems to have worked really well (so far)!