Goliath Drows are some of the largest type of Drow in Skylanders: Spyro's Adventure. They attack by charging at your Skylanders with their two shields, one attached to each arm which they draw together as they charge. As they charge at your Skylanders, the shields will glow green and spikes will form on them that protect them from any attack.
The Goliath Drows made a reappearance in Skylanders: Giants. One notable Goliath Drow is Brock, who is larger than the other Goliaths, and was at first a villain, but turned good after the Skylander defeated him.