Servo

 was a maintenance droid on the Haven that rescued the Eighth Doctor from the cannibalist. It wanted to know what the Doctor was as he wasn't a robot. All it wanted to do was write poetry, as it felt emotions. Servo's poems were written in hexadecimal machine code. It told the Doctor about Minerva.

The Doctor believed that Servo was greater than any robot that came before him, and called him a miracle of evolution for developing the drive and capacity to create poetry, after a computer virus allowed for free will by failing to destroy the Haven robots. (AUDIO: The Cannibalists)