After finding and befriending Sherry, Leon and Claire reach a strange room where Chief Irons is located, Leon recognizes the Chief while he mentions a "G", the Chief recognizes Sherry as William's daughter but before he can do anything else, he starts turning into a monster.
Brian Irons: Isn't she beautiful? I was about to stuff her.
Leon S. Kennedy: Chief Irons...?
Claire Redfield: You know him?
Irons: Prowling around at a time like this. You're after G, too. Aren't you?
Irons: Don't play dumb with me!
Aren't you Dr. Birkin's...
Leon: Hold on! We need to stop this thing first!