It's spawned by Kreator. Kreator is an elite, So pets will ping it, despite being in desert. Ive found one spawn. 204/294 DK takes a minute or 2 to kill, charge has a knockdown, but minimal damage is taken. The 2 spawns it summons are also easy and do minimal damage.

you need to complete Valencia II main quest
and go back to SAND GRAIN BAZAAR talk with Barhan Nesser for take quest Suspicious Aakman
do quest until quest : A True Unknown Danger to the Desert you ll got knowledge
ps.don't kill Kreator just slow damage

You CAN get the knowledge without valencia 2 but doing val 2 first lets you guarantee a kreator spawn, he will however spawn by himself anyway at random.
If you do the val2 way after finish the questline go back to sand grain bazaar and talk to Barhan Nesser, it needs to be the sand grain version who moves there during the main story. Do the questline starting with suspicious aakman up to the step called a true unknown danger to the desert, you can then find kreator by simply checking world map.

Regardless of which method you choose to find Kreator you then wanna get him to 50% hp (be careful, i accidentally oneshot him more then once, ended up simply lmbing him to 50% ), he'll then spawn 1 Alten and 1 Kalten, kill them off for a knowledge roll, then simply run away from Kreator until he resets and do it over and over til you have S knowledge (If thats what you want obviously).