"A growing family, whose only goal in life is not to get eaten, they're always ready to sing for their supper - instead of being your supper. As Rizzo's mother once told him, "You should never eat singing food;" these vegetables would really appreciate it if you took her advice. Besides, they sing better than they taste."
Every Muppet has different things that they like. For every unique object that they like that's placed on the stage, the Muppets's happiness will increase by one (in other words, placing two of the same liked item will still only increase happiness by one ).