Private Callow was a dead soldier autopsied by Dr. H. Lector of the Sierra Army Depot in 2077.
Background
The cryo storage crew played a practical joke on the doctor, by rewiring his organ extractor to remove Callow's colon. Lector didn't take too kindly to that and sent them private Callow's cooked liver, together with fava beans and a nice Chianti.
Behind the scenes
Reference to Hannibal Lecter, brilliant psychiatrist and cannibalistic serial killer (a fictional character in a series of novels by author Thomas Harris: Red Dragon, The Silence of the Lambs, Hannibal, Hannibal Rising). Lecter's cuisine habits were referenced also together with Chip's spleen quest (liver with fava beans).