their bottoms are made out of springs

A sad day for America:

Paul Winchell, voice of Tigger, dies in Calif.

Winchell was also an inventor with a patent for a prototype artificial heart he built in the 1960s in the same workshop in which he created his ventriloquist dummies, Blue Star said. He also created an "invisible" garter belt, a flameless cigarette lighter and an early version of the disposable razor.