They have a Cave Troll...

Troll, Cave

Armor Class: 18
Hit Dice: 7*
No. of Attacks: 2 claws/1 bite or 1 weapon/1 bite
Damage: 1d6/1d6/1d10 or by weapon/1d10
Movement: 40'
No. Appearing: 1d8, Wild 1d8, Lair 1d8
Save As: Fighter: 7
Morale: 10 (8)
Treasure Type: D
XP: 735

Evolutionary cousins of the more widespread forest troll and scrag, or river troll, cave trolls, sometimes known as mountain trolls, are easily distinguished from their brethren by their grey, lumpy skin, bulkier frame, and diminished noses. Cave trolls lack the feral cunning of their cousins, though they have a somewhat greater aptitude for (extremely rough) speech and tool use, often brandishing heavy branches or even crude spears in battle. Although like all trolls they are fast healers, a cave troll's wounds mend in hours rather than minutes, and it has no affinity for regrowing lost appendages. Its primary means of defense instead lies in its extremely thick, rubbery skin, which is studded with rock-hard osteoderms like those of an Ankylosaur. So well-protected is a cave troll's hide that nothing short of a magic weapon can pierce it (though like all trolls, fire and acid have also proven deadly to them). Cave trolls also fear the sun, and are scrupulously nocturnal, for it is their greatest weakness. Exposing a cave troll to direct sunlight disorients it: It can act for only one round and is turned to stone in the next round if it cannot escape. Use the morale value in parentheses if a cave troll is confronted with fire, acid, or bright lights (at least the equivalent of a Continual Light spell). Cave trolls stand ten feet tall (when they manage to straighten up to their full height) and commonly reach a ton or more in weight.

Stats given are for BFRPG, but I'm sure you know how to convert the parts that need converting for your system of choice.