A large, relatively valuable marble in children's games.
Any of various butterflies of the subfamily Charaxinae.
Specifically, the ruler of the Holy Roman Empire; the world-monarch.
Any of various large dragonflies of the cosmopolitan genus Anax.
An emperor penguin.
The fourth trump or major arcana card of the tarot deck.
The male monarch or ruler of an empire.
Any monarch ruling an empire, irrespective of gender, with "empress" contrasting to mean the consort of an emperor.
Any fish of the family Lethrinidae.
An animal which has a genetic recessive variation that causes the guard hairs to be very short or fully lacking.