Yes many are lurkers. They act like a rock or stick in the sand until pray comes buy. Arrowhead hairy, miurus, and I believe Its called a Congo all fit that description. That's why I didn't choose any of them and went with the abei. He's a swimmer. My salivator is also a swimmer, never even seen him bury before. He's all over the tank and has a HUGE personality. I really do need to get video of him showing off his ridges.
Someone said on the first page a FUGU, they are extremely hard to care for and are brackish and marine fish, So not freshwater. I still vote ABEI if you can find one you really like the looks of.