Police responded with a knife around 7:30 p.m. in the area of Beverley Street and Dundas Street West, east of Spadina Avenue.
Police said two men were involved in a verbal altercation in an apartment building.
At one point during the fight, one of the men took a knife from his unit and stabbed the other in the chest, police said.
He then fled the scene. The victim was taken to hospital with life-threatening injuries.
On Sunday, police released images from security cameras of the suspect, who is described as five or eight legs with a slender body, long red ponytail and long red beard.
He wore a black hat on the back, a dark backpack, a brown camo jacket, a white / cream shirt with buttons, dark trousers, black shoes with white soles.
Police ask anyone with information about the suspect and where he is to contact investigators at 416-808-5200 or Crime Stoppers anonymously at 416-222-TIPS (8477).
