I have a 5-6 inch fox, had him for a few years now.
About a year ago I went on a trip for 4 days, left the tank under the care of my friend. My fish are used to getting fed 2-3 times per day. My friend was only feeding them once a day. Apparently this wasn't enough for the fox face because when I came back here had eaten 3 trachys and one donut coral. Pretty expensive snacks. Before this he was never an issue, but I know it was him because my friend said the spike yellow one kept biting them and taking flesh off.
Apart from that he's super good now but I don't keep any meaty corals anymore just o be safe. His color got super nice tho from eating them 😂