Now I am going for a theme here, starting with tadpoles – yes you are correct there are TWO models here, but they are variations of each other – one without legs, the other with … look closely:
Quite cute models from a purely biological perspective because when the legs form, the tail is absorbed into the body much as the model suggests. each made from a square 1/4 the size of the largest one you can cut from an A4 sheet.

We all know a tadpole develops into a ….