Beige Guardian

The Beige Guardian, a counterpart to the Black and White Guardians was a character who featured in a video game that Izzy Sinclair played on the Time-Space Visualiser. In this game he collected together every enemy of the Doctor's and then the first eight incarnations of the Doctor and tied them up and placed them on a huge cake.

After leaving the other six to go and fight against their enemies, he left the Doctor's first and eighth tied to the cake. They both worked together to break free of it, and they both deduced that all the Beige Guardian was, was just a gathering of electrons who destroyed with the sonic screwdriver. All the other Doctors then reappeared by the cake. (DWM: Happy Deathday)

Behind the Scenes
The character of the Beige Guardian in Happy Deathday resembles the actor David Hyde Pierce in his role of Niles Crane from the situation comedy Frasier.