This two-toned lobster, caught earlier this week off the New England coast, looks like he's dressed for Halloween. But the split coloration isn't a costume at all—it's an incredibly rare natural occurrence. How rare? Try one in 50 million.

But those numbers only earn the orange-brown split-colored specimen second place on the list of outlandish lobster styles, of which there are several others. In each, a genetic mutation silences one or more of the red, yellow, and blue pigments that together make up the typical lobster's brownish hue. Check them out below, in order from least to most rare.

1. Blue Lobster

The blue lobster, one of which was caught by a teenager last August in Maine, is comparatively common, appearing at a frequency of about one in 2 million.

2. Yellow-Orange

Last summer, the New England Aquarium acquired a yellow-orange lobster, which might not be as immediately striking as the blue variety, but actually appears even less frequently, closer to one in 30 million. In the video above, the aquarium introduces the new addition to their other uniquely-hued residents—including a two-toned specimen of their own.

3. Two-toned

Like the other rarities above, the split-coloration is the result of a genetic mutation relating to pigment activation. But the near-perfect division of color is believed to be caused by a complete cellular split when the lobster egg is first fertilized. Because of this dual development, split-colored lobsters are often hermaphrodites as well.

4. White

The rarest of them all, the white or albino lobster, appears once in every 100 million. In fact, seeing even one is so unlikely that when two turned up within a week of each other last summer, experts expressed some skepticism that they were true albinos.