Which is the un rarest Webkinz?

That mostly depends on what you think. But some of the rarest, (and the most expensive too!) are:

Cheeky Dog

Cheeky Cat

Love Puppy

Sherbet Bunny

Magical Retriever (trading cards)

Mystical Panda (trading cards)

St. Bernard

Unicorn

Horse (the original one!)

Basset hound

and the Monster ( Online only)

Hope this helps!

~Goldendoodle~