a few months ago i was offered what the garden centre called a " chochlate catfish " it was like a big square flat jaw/mouth and burrowed really far into the sand and didnt really move i was gonig to get it but it was 40quid so i didnt any ideas what this was and what its compatibilty is as ive googled the name but im abit crap at googly thanks alot 

did you not read any of those links I just gave. Or did your own subsequent research?q`