He told fans at this year's Comic-Con that the character may feature in the forthcoming sixth season.
"I see a moment when the boys have to fight a tiny pinprick of light that ultimately turns out to be Tinkerbell," he explained. "I see Jensen [Ackles] with a little light coming towards him and he goes, 'It's so beautiful'. You can clap your hands in this story and believing won't help."
Edlund admitted that the idea was "insane" but promised that the final episode would be "rich with absurdity".
Supernatural returns to The CW on September 24.