I've seen people keeping the bigger type of wolfish with bichirs. I had a smaller kind of wolfish with my bichirs.
Hao I kept a smaller one for awhile, biggest issue was tank cleaning time. If I was arranging decor and my hand got to close he would bite me. Bloody thing drew blood several times.
It disappeared one day, I suspect into the goby.
The wolf never bothered the bichirs