Urugorak is replaced by Aberrant Urugorak on Challenge Level (ChLvl) 1 and above. One (ChLvl 1-2) or two (ChLvl 3) Aberrant Urugoraks spawn once 5 Spikey Eyepods have been broken. Aberrant Urugorak has much more health and damage, but otherwise behaves like Urugorak.
Only one Urugorak or (pair of) Aberrant Urugorak(s) spawns per Desolate Canyon planet. To fight (Aberrant) Urugorak(s) again, one must travel to another Desolate Canyon planet.
Before the fight, kill everything you can before engaging with any rock worms; this will allow you to focus on just Urugorak. Urugorak moves faster than you can run, so you will need to dash if you are to outrun it in a straight line. The best way to fight it, however, is to position yourself in the center of its turning arc, adjusting your position as necessary. Urugorak, like other worm enemies, turns with rather wide berths, making it possible to lead it in circles while continuously attacking.
Being a worm-type enemy, each of Urugorak's segments has its own hitbox. Use piercing attacks like Blaze, Shock, and Photon Blade or area of effect attacks like Plasma Grenade and sword swings to damage multiple segments in one attack. This will significantly increase your DPS while fighting the boss. Using the Colossus in particular is a good idea, due to its very large hitbox.