The Agent Room is a special metaroom created by Chani that occupies the position of the C3 Creator, allowing agents originally intended for Creatures 3 to be injected into a DS or Edynn world. Note that just because you can inject it does not mean it will work - if the agent really does need C3, this won't help!
The Agent Room can be downloaded at an archive of Caisleáin Uaine.