as a baby it would be ok. if you mean a ten gal. for its whole life then yeah i'd go for a frog or gecko of some sort...ten gal leaves things kinda limited i saw rosy boa as one of his possibilities so i figured it would grow out of the ten gal. and if he wanted a snake then i suggested a ball python as a first snake that is a great pet
As long as you can provide appropriately sized food they're pretty simple from what I hear... Most are pretty small and require things like springtails and fruit flies, but if you get a larger species like P. terribilis you can feed crickets...
I would say a Kenyan sand Boa. They are totally cool and grow small (male). Second will be a Male Hognose snake and third a fat tail gecko.
I think a frog would be too delicate and would look best in a planted cage that will require extra supplies like UV lights. If you want an easy to care for frog I would go with the fat, pacman frogs. They will eat anything!