Animal
     |
  Mammal
  / / \  \
              /  /   \    \
            /   /     \     \
          /    /       \       \
        /     /         \        \
      /      /           \         \
    /       /             \           \
  /        /               \             \
Dog      Cat      Raccoon      SwampThing
     (implements) (implements) 
     ( Washer   )   ( Washer   ) 

Consider the following code:
1.  Cat sunflower;
2.  Washer wawa;
3.  SwampThing pogo;
4.  
5.  sunflower = new Cat();
6.  wawa = sunflower;
7.  pogo = (SwampThing)wawa;