The Pussycat Swallowtail (Satyrinae lexipus) is a rare tropical butterfly that Lord Beasley Waterford tracks down to the South Pacific. Local natives direct him to Gilligan's island where Waterford tracks it all over the island and finds it in yellow and red variants plus a blue imposter. The Skipper tries passing off a fake of it at one point, and Gilligan swats it away once. Nothing is known of its biology or habits.
- There is no such butterfly as a "Pussycat Swallowtail," however, there are Swallowtail butterflies.
- Lord Beasley calls the Pussycat Swallowtail the rarest butterfly in the world, the only one to escape him, but then he learn there is an even rarer butterfly in the Antarctic, the only place on Earth where butterflies do not exist.
- Other butterflies the Professor discovers are the Satyrinae Butterfly with bright yellow spots on her wings, the Nymphalidae which builds a shelter out of rolled leaves, the Papillionidae or Milkweed Butterfly, the Nymphalidae antiopius, the Basilarchia or red-tailed butterfly, the Larchae artemis, the Nymphalidae artemis and the Lycenidae or Meadowbrown butterfly, a bright red butterfly with spots of brown.