It's like this...
Batesian mimicry - you can't defend yourself, but you mimic an animal that does a really good job of protecting itself. For example, say there's an animal who is poisonous and is red. The predator tries to eat it, learns it's poisonous, associates the poison with the red. Another animal has no poison, but figures if it turns red, the predator will think it's poisonous like the other one. Free protection.
Mullerian mimicry - One animal's yellow and black, and stings. Another one is yellow and black, and stings. We all get grouped together. "Yellow and black! Must sting!"
Make sense?
aranjuez