These guys are ambush predators. They don't move much hence the name 'cows'. great fish but not active. I believe it needs other fish to eat if not trained to frozen foods.
i had one that i bought at 10 in for $35 but watch out at 13 in he ate my 5 in green terror and my 6 in devil then choked to death. The only thing that worked with him were my 8 in jags