A snarly sharp tooth growth at the top of a malicious vagina. This tooth retracts once a penis is inserted, then catches onto the main vein of the penis when exiting the vagina. This tooth then rips open the main vein causing a massive loss of blood and permanent damage to the penis. This violent attack leaves mammoth amounts of scar tissue across the top of the penis once healed, resulting in a a "captan hook".
"My penis curves straight up when I get a boner because it got caught in that girls gator tooth."