Thanks God that friendly creature
I named it ""creature" cause they come out only at night, when morning they all gone!
I am not sure if they are bristle cause I made liverock by myself, but one night I found kind of worm too but very slowly tenctacle(this is the real creature very hard to take on picture/sensitive of light) playing seek and hide
and here mr. meshy (detritus)
RIP! I bought yesterday then I found it this morning
I think lobter is the suspect!