What's the rarest animal you've seen in person?

When I was a kid, on a trip to Paris, I went to the zoo, and the highlight of the whole trip was seeing an Aldabra giant tortoise (listed as vulnerable by IUCN). Now, even when this was 1990, I was still like "ooooooo cool turt". I didn't expect the buddy to jump around and munch pizza. Just a tortoise doing tortoise things slowly.

(The other highlight of the trip was seeing a public Minitel terminal. Holy shit guys, we were only mildly approaching that level in Finland.)