Easy process to find a tek rex on the island in UME:

1. Go to carnivore island

2. Bring a strong tame that can decimate every creature there (i usually bring a carcharo cuz it can 1 shot almost every creature there)

3. Kill any raptor, sabertooth, carno, argy, and rex that spawns there and continue for as long as you can until you see a shiny, metallic rex that looks robotic

4. If you're on singleplayer, then here are some bonus tips:

4a. I recommend backing up a save file every time you see a supply crate reach the ground since every time you enter your game a supply crate will be guaranteed to spawn near you shortly after. (You can also use this to farm keys since you wont need fo fly miles at a time to check every supply crate since if you're at carno island every supply crate that spawns WILL ALWAYS be on carno island unless you leave) If you can't kill everything on carno island once before the first supply crate reaches the ground, then back up a save every time you kill a rex or 2.

4b. If you find an alpha raptor, carno or rex and you need better gear you can back up your save and then kill the alpha to have a chance to get hide armor, sickles, pikes, metal axes, metal picks, crossbows, bows, and finally simple pistols (sorry this doesnt include swords). Chitin armor can also drop from alpha carnos and alpha rexes, and when paired with a high enough difficulty level and good enough luck, you can get a mastercraft or ascendant piece of chitin armor that can be stronger than a primitive flak piece (100 armor)

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