Groupmates from Hell

Teachers usually group students in order to promote camaraderie and cooperation among them. But sometimes, groupwork may become a traumatic experience.
Working in a group allows students to collaborate so that achieving a certain goal would become a bit less of a drag. This is true if the members respect the ideas and work of each other and are enthusiastic to participate in the group's activities.
However, there are people who tend to drown the whole group, plummeting it into the abyss of failure. Meet the groupmates from hell. Although they're part of the group, they prefer to be alone and invisible. They don't cooperate, and they just wait for someone in the group to salvage what's left of the group's dignity, as if they don't have dignity themselves. They are so lazy and doesn't care what will hapen to the group. They are parasites. People like these don't have the initiative to help. They let the hardworking member(s) perform all the tasks. The hardworking member might be risking his/her life to do the job, while the lazy ones just sit there and watch -- with their blank thoughts.
What's the point of having a group if just one person performs everything?
What's the use of the others? Moral support? -- The hell!!!
People like these make life really hard for those who are actually putting so much effort into the work.
And what's worse? The uncooperative members receive an equal credit with those who really worked hard.
They should be ashamed.
It is so unfair.
I'm sending these members back to hell.