When I shipped reptiles back in the day, I used to use appropriately sized fish boxes with the styrofoam inserts. I would poke holes in it for air, put the snake or lizard in either a container or a pillowcase/snake bag, crush up some newspaper for some cushioning and box it up. Depending on the weather report for that day for your, as well as, the receiver's locale, you could add either some hot packs or cold packs in the package to ensure that the animal would not freeze or cook. I also marked the box "LIVE HARMLESS LIZARDS" or something of the like. Check with the courier to make sure that they accept such packages though.