Hedgehogs were a species from Earth.
Sarah Jane Smith once said that she looked like a startled hedgehog with her hair up. (AUDIO: The Ghosts of N-Space [+]Barry Letts, BBC Audio Dramas (BBC Audio, BBC Radio 2, 1996).)
In 1989, Alistair Gordon Lethbridge-Stewart was aware that Sonic the Hedgehog was a blue hedgehog. (PROSE: Business Unusual [+]Gary Russell, BBC Past Doctor Adventures (BBC Books, 1997).)