A gecko is a good pet for a 12 year old and especially a Leopard Gecko and Crested Gecko.
The best lizard for a kid is a Leopard Gecko or a Crested Gecko.
Leopard Geckos as well as Crested Geckos are very popular lizards for kids and they are very easy to care for and have a docile nature.
Both Leopard Geckos and Crested Geckos are able to tolerate handling and make them great pets for beginner reptile owners.
Leopard Geckos are easy to handle, very harder and passive and are also not intimidating to children and can also be tamed easily.
However they are prone to runaway as they also have good speed.
Leopard Geckos primarily eat insects such as roaches, mealworms and crickets and they average in size of around 7 to 10 inches long.
Crested Geckos are also easy to care for and keep and come in a range of patterns and colors.
Crested Geckos are also sensitive to high temperatures and also eat a mixture of insects and specialized crested gecko foods.
Crested Geckos are also small and relatively fragile.
Other good lizards for kids are Blue Tongued Skinks and Bearded Dragons.
Bearded Dragons are lizards which are also non aggressive and calm and are friendly and easily respond to their owner's voices and can be taken out of their cage.
Blue Tongued Skinks are docile and easy to handle as well as being low in maintenance although they can also grow large.
Most lizards live for 10 years or longer depending on the species and they should also have a properly sized habitat with proper lighting and heat.