DJ - the ones commonly sold in Walmarts are not the clawed frogs but rather the smaller cousin Dwarf Frogs. Those never grow larger than about an inch and aren't as prone to "Houdini" acts in climbing out of their tanks like the clawed frogs.
Clawed frogs are actually banned in a number of states, including California because they become problematic candidates for species invasion when they get loose and can mess with local wildlife populations. Last thing we need is another "Cane Frog crisis" like the one they're dealing with over in Australia.