SCP-939 can be tamed if you get inside it
When i trapped 939 in workshop room behind the glass and opened the orange door i peeked inside, 939 got agro, i stopped peeking as he ran at me, i stayed by the door frame 939 came out the door, ran inside me . he was still performing the bitting animation but was not doing any damage as i was not in the reach of his jaws. i was in his belly! I have done this multiple times and it always worked plus I got whole thing on video.
(I can send the video on discord i you want to.)