Your title reminded me of when I was a little girl in the 1950s. My mother used to have one of these
and when it was my birthday she would make a red jelly rabbit and sit it on a serving dish on chopped green jelly. I thought it was the "bees-knees". Other children who came to my birthday party were always very impressed!
My aunt "inherited" it for her sons when I grew out of jelly rabbits and one year she made the rabbit with chocolate blancmange - I was SO jealous!!!!