Satyr

Satyrs, sometimes known as fauns, we're creatures which resembled humans with goat legs, pointed ears, and horns on their heads. They were notoriously stupid and only interested in sex. They were the servants of Hades. (PROSE: Deadly Reunion)

Extraterrestrial life forms which resembled satyrs included Dæmons and Vegans. (TV: The Dæmons, The Monster of Peladon) A satyr-like child of an unknown species was captured and brought to the Edifice. (AUDIO: The Forever Trap) Satyrs were native to Antimasque. (PROSE: The Book of the Still)

The cybernetic stewards of the Crystal Bucephalus resembled silver and gold satyrs with diamond-encrusted horns. (PROSE: The Crystal Bucephalus)

Behind the scenes

 * According to non-narrative information in The Brilliant Book 2012, Satyrs, Cyclops, and unicorns were pests in London in River Song's World.