Crawfish

[Cyera]

Ok so I have a question I just got a craw fish and since I have lost 2 of my Molly's one was large orange and other was a small Dalmatian Molly the small one was missing tail and fins and a chance out the head but large just the tail could my craw be killing my fish I red wag platy and guppies and Molly in a 30 gal tank

 

[Gruntle]

In general, fins and claws don't mix. I would say there's a fair chance your crawfish is trying to eat your finned fish.