They consist of a transparent, water-filled case housing a thumb-sized figure, and a base with a microchip, microphone, and speaker to register and respond to sounds made by kids or by other Aquapets.

The first three characters of the original Aquapets (Miku, also referred to as Kiko; Puku and Tu) were sold exclusively at Toys R Us stores starting in February 2004.

By April of that year, the initial three figures were joined by three new characters (Kadet, Bunni and Stinga) to complete "Wave 1" which were available in mass and specialty stores across the country.

In March 2011, Wild Planet released New Aquapets - redesigned and reprogrammed versions of eight characters from previous collections, Bebe, Bertie, Bunni, Fizzie, Fretta, Harf, Puku and Squirt.

In late 2011, "Wave 2" of the New Aquapets were released; consisting of Tu, Miku (renamed to Muki), Purkle, Likabee, Zmooch, and Kitzi.