First Quality Comics appearance in Blackhawk (Quality Comics, 1944 series) #50 (March 1952), with Reed Crandall art.
First DC Comics appearance in Blackhawk (DC, 1957 series) #108 (January 1957), with Dick Dillin and Chuck Cuidera art.
See also the [World War II Killer Shark][31632].
[31632]: https://www.comics.org/character/31632/