I remember these things from the 90's too. At the mall i worked at they had a little kiosk set up where they sold them. All of us who worked at the pet store were horrified and would visit them daily with complaints. We had alot of people come into the store to ask about them. A lot of people left angry, but with proper tanks and supplies, when they found out the truth about aquababies.
I still remember the "care" sheet that came with them. It went something like this
1. Use bottled water to refill the tank when water evaporates.
2. Don't feed them, they'll eat the plant.
I hate aquababies with a passion. I'm glad I haven't seen any for sale in years.