Centrifugal casting (high speed, single axiis casting of white metal or cold resins, aka 'spincasting') or Rotocasting (slow speed, bi-directional cold resin casting) are processes most manufacturers use to produce Urban Vinyl toys - at least, the ones specifically made out of polyurethane. Spincasting produces solid casts, rotational casting (rotocasting / rotacsting) creates hollow casts.
The rotocasting process works like this: A liquid form of the material to be used is injected into a mold, and the mold is spun on two axes (as in "more than one axis", not "more than one axe"). The plastic flows along the inside edges of the mold, coating it evenly, while remaining hollow in the center. The main advantage to this process is it uses less plastic, meaning the toy is lighter and less expensive to produce. It also means that an item can be made bigger - some rotocast toys are taller than 13 inches. This process can be used to make boring things like jewelry and telescope mirrors, but I think you'll agree the best use of the technique is for toys. And chocolate bunnies.