Easy to knock out of you have skiff. I tried to use a cannon with a trap but it always wrapped before i could knock it out. I tried the rockets but that seem to didn't work either. The skiff knocks them out quick. Just be careful of the meteor shower. Lost a lvl 135 right after I tamed him.
Singleplayer taming is so hard. I had nobody to aim the cannon, and I'm currently waiting for the astercetus to wake up. I struggled so hard. He's a blue level 8. LEVEL 8. Dododex says there's a 93% chance of death for the cannon for a level 8.. Pretty lucky, eh? Singleplayer taming is.. Hard. Not impossible, though. I managed!
Don't use mek because the astrocetus takes first the torpor and then the damage. The effectiveness will go down.
We tamed a 130 with mek and Kibble and get a 136 -.-
I think the stronger the weapon the more you loose the effectiveness, so the "best" way is to knock out with rocket launcher.
It's the same effect with rock elementals.
Wildcard should repair that.