List of intelligent species on Earth

A list of intelligent lifeforms on Earth, that are given rights and allowed to live amongst human society.

Note: This is only listing species in the 20th century.

Vortigaunt
Xenotherium subservilia, known as vortigaunts or "vorts", are a wise humanoid species. Their home planet was invaded by the Combine, causing them to flee to Xen, where they were enslaved by the Nihilanth. They later assisted human forces during the Ten Day War, and later became the first aliens to join human civilization after the ensuing Alien Rights Bill.

See also: http://half-life.wikia.com/wiki/Vortigaunt