Make a 3x3 stone floor surrounded with 2*height double door frame. This will make a cage that you can enter and get out simply but not the therizino. Then add some rams/stairs leading into the cage. Lure the therizino into the cage and knock it out easily with tranquil arrow. This cage trap can be built on a raft as well.
Most horrific thing I’ve seen so far. I hate them, if you’re a low level, literally avoid them at all costs, unless you want to die.
They might seem nice from a distance, until you get close and then they murder you before you have the chance to run away
Don't make the same mistake i did. I was taming a therizinosaurus and i left it alone for 30 seconds for water. When i come back, a pack of raptors came in and murdered him. WATCH YOUR TAMES PLEASE I FEEL SO SAD RIGHT NOW