on its pure form they are tension fields
Metaballs are great muscle-fakers, it were a fever with them a pair of years ago, but never really caught, it seems we artists prefer to fake it manually...
(Delete if aplicable)
Look at what one can make with blobby/sticky polygons (and 3dsmax 3)
this was a real cool company to work for, time ago, but they had popular prices instead of studio prices, so they didnt really survived... (they are still there but they are 4 cats and i doubt they are doing more than surviving)