No, this is not a thing. I worked as camp counselor for 3 summers and have many, many friends who also worked as counselors at various locations. I have never heard of this. I don't think it's necessary. Honestly, most parents didn't even bother to meet me or say hello before they took their kids home. I always thought that was weird, wouldn't you want to at least shake the hand of the person who took care of your kid for week?! But anyway, no, I don't think your kid's counselor will expect a tip or gift. If you want to do something nice, make it a point to meet them before you take your kids home. Shake their hand, look them in the eye, and say "Thanks" and that will be enough. Camp counsellors get paid next to nothing, but they are well aware of that going into it and they generally get free room and board for the summer. Most of them do not work at a camp because they need the money, they work at a camp because they want to have fun for a summer. All my friends who needed the money got real minimum wage jobs.