The group, which asserts it has surgically altered 300 dolls, says its aim is to startle the public into thinking about the Stone Age-world view that the dolls reflect.

The result is a mutant colony of Barbies-on-steroids who roar things like "Attack!" "Vengeance is mine!" and "Eat lead, Cobra!" The emasculated G. I. Joe's, meanwhile, twitter, "Will we ever have enough clothes?" and "Let's plan our dream wedding!"

Included with each doll is a leaflet from the group, claiming credit and calling itself, appropriately enough, the Barbie Liberation Organization. The leaflets list the group's telephone number, as well as those of television stations and newspapers in the area where the doll was purchased. Buyers who agree with the group's anti-sexist, anti-violent agenda are urged in the leaflet to call these news organizations.

A B.L.O. spokesman, responding to a message left on the group's answering machine and identifying himself as "G. I. Joe," said: "Obviously, our goal is to get media attention. We are trying to make a statement about the way toys can encourage negative behavior in children, particularly given rising acts of violence and sexism."

It is impossible to verify the group's assertion of sabotaging 300 dolls, because the only confirmed alterations so far have been about a dozen that turned up in Albany, San Diego and Walnut Creek, Calif., where consumers have called local papers or television stations and described their surprise at learning of their dolls' little secrets. Amazement at One Store