A museum exhibit volunteer at Drexel University got an incredible surprise last fall, when he came upon a half-male and half-female butterfly just emerged from its chrysalis.

Chris Johnson, a volunteer for the university's Academy of Natural Sciences, was working on an exhibit called Butterflies! in October when he noticed a brand-new butterfly slowly opening up its wings.

The butterfly's two right wings were brown, with white and yellow spots, while the left wings were darker, with blue and purple markings.

"The wings were so dramatically different, it was immediately apparent what it was," said Johnson in a statement. The volunteer was looking at a butterfly that was exactly half female and half male.

"I thought: 'Somebody’s fooling with me. It’s just too perfect,'" Johnson added.