Beowulf

 was the greatest warrior Denmark had seen. When he found Ace under his table he chased her round the dining chamber. He thought she was a Valkyrie. He thought the black TARDIS was Valhalla.

Many years later, he was a king, and thought that Sally Morgan was a Valkyrie, and Hex was a mortal. He had the Seventh Doctor's sonic screwdriver and Garundel's robot. He was unsure when Wiglaf saw the white TARDIS and thought they were demons. (AUDIO: Black and White)