Ten of the best aliens in science fiction

For the Guardian, John Mullan named ten of the best aliens in science fiction.One entry on the list:TralfamadoriansIn Kurt Vonnegut's novel Slaughterhouse-Five, Billy Pilgrim is kidnapped by these inquisitive and fairly benign aliens, who put him in a zoo. They look like green toilet plungers. "Their suction cups were on the ground, and ... at the top of each shaft was a little hand with a green