Stores in your neighborhood probably have Grow-a-Frogs available for you. Most 'education', 'learning', 'teacher', 'imagination', and 'science' stores carry Grow-a-Frogs.

Toy stores are also a great place to find Grow-a-Frogs. Be sure to look in the educational science products section.

Educational catalogs are a wonderful place to browse.

By the way, Grow-a-Frogs are never "mass marketed". They are NOT in 'Superstores' or Supermarkets !!