Pliff is shown to be a green Plonster With a Tail on his back and his friends are plummy The Orange Plonster With a pointy head and plops the blue Plonster who is the cranky one sometimes and sometimes he misses Pheobe And Thomas Over And Over Pliff And Plummy tell plops that if they saw the train and he said they didn't so they created another train called "The Plonsterdorf Express" and they go and follow after them