Make a taming pen. Put mejo berries in your last slot and let the pega steal it. After it steals the berries use a whip to take it out of its hands and it will steal from you sooner. Only way to tame a 150 it seems since its taming bar goes down while it holds the berries.
I have discovered the way to easy tame these things!! What you need to do is trap the pegomastax in a closed area and have two tribe members with a bunch of mejo berrys ( make sure you always have a stack of 100 in the last slot of your hot bar) make sure both of the tribe members are standing next to each other and when the pego attacks ( robs ) you it will hit both of you at once making the taming a lot quicker and easier !! You're welcome !
When tamed, they can pick-pocket other players. If you get on of these early game, use it against other players. Just make sure you can get away without dying. (Also, they can ride on your shoulder, making them a nice companion to have. After pick-pocketing someone, put it on your shoulder and run away with the goods)
Calculator needs to be updated. I just tamed a lvl 30 and it took me 1,000 mejo berries. That's on an official server with 1x taming. Says it should have been 22 berries. And crops wouldn't work on taming either.
Have a chamber surrounding important rooms in your base filled with narc traps, bear traps, dimorphodons, troodons, and these little guys. The traps will either trap/KO raiders, the troodons will tranq them, the dimos will kill them, and the pegomastxs will disarm them. This has defended me from 10+ attempted raids
Many if not all ground mounts don't protect you from being robbed, so while I used to argue that a fast raptor is as good as a bird you'll have an empty inventory when you get there soooo I guess the fun's over