Videos generally struggle on this site - most people upload them to video sharing service like YouTube, then link them here.
Currently, your video is available as (fairly large) download.
Anyway, the worm there may be Oenone fulgida. If so, it's predatory and will eat things like bivalves (including, reportedly, Tridacna clams) and snails - it's not something most people would want in their tank.