Troll

The troll, a veteran of the Horde, lost memory and an arm in his last battle. A goblin caravan found him, unconscious, and made him a one-of-a-kind prosthesis. For some amount of time, he had been living with the goblins, but then he left to find his calling, getting a combination spear-crossbow.
These days, he is a lone mercenary.

The crossbow, when folded, is used as a spear.
The prosthesis has an integrated radio transmitter for the crossbow's trigger.
Bolt magazines are strapped on troll's belt.

Troll with goblin prosthesis for the Digital Painting Classes challenge