I tamed my eerie male scorpion on ark mobile during the eerie server event inside the poison cave. It was the best choice I ever made as he is now guarding my hatchery.
On mobile I recommend the following for stats if you plan to use a scorpion as a guard.
Speed is good at 230%
Melee at about 500% (just to keep those nasty wild Dinos spawning in your base in line)
Health about 5k (scorpions can be very easily killed if they don’t have good health in them.)