Listen to I Saw a Deer Today online. I Saw a Deer Today is an English language song and is sung by Aperture Science Psychoacoustic Laboratories. I Saw a Deer Today, from the album Portal 2: Songs to Test By (Original Game Soundtrack) (Collectors Edition), was released in the year 2012. The duration of the song is 3:15. Download English songs online from JioSaavn.