Kirix has two abilities, first he charges you then does a green aoe that sucks the life out of you in about 3 seconds. I am on my tanking gear with 150k health but still died taming him up front, spewing his green goo on me. He is also immune to all traps, so the freezing trap trick won’t work.
Here’s the “Kirix taming strategy” I did to get him, I set my Aspect of the Wild to get nature resistance, then waited for him to be in range of my concussive shot. Pewpew! He’s pulled but slowed, I then braced myself for his charge attack that throws me up in the air. The next button I mashed was Scatter Shot, while he’s dazed (and confused what hit him), I popped Deterrence and then began taming. After a few seconds of watching some small little hearts flying up… I got him.
To sum it all up:
Aspect of Wild + Concussive Shot + wait for his charge attack + Scatter Shot + Deterrence + Tame Beast = A cool green fire spider