Term defining a large truck or group of people that obstructs the flow of traffic, either intentionally or unintenionally. Taken from Starcraft, where Ultralisks commonly block up base entrances by accident, preventing zerglings from entering or leaving.
Doug: Dammit, this semi is being a real ultralisk.
Steve: Well, I think you'll get a shot at passing it in a second, oh wait, he moved to keep you from passing. What an ultralisk.
The act of achieving Level 10 in Evolves FFA Choice before anyone else(A UMS game variant for Starcraft), and using the Ultralisks to "sweep" through the much weaker ground units that your opponents have. Also known as ultra sweeping, sweeping, sweep, etc. Popularly used by TeHNeWBON.
Ultratasking-I was on the toilet, working on my laptop, talking on confrence call, watching the football game, and eating a slice of pizza & coke when I decided this would be a good time to clip my toenails.