Louis Marx Toy Co. 1967. 6″ tall.
The Marx figures are molded plastic, and were originally released in grey, but you will typically find them in four different colors — bright red, blue, orange, and green — and a limited number of sets were also sold prepainted. The figures were later reproduced in brown, dark red, and silver.
In addition to Hulk, there were figures for Spider-Man, Daredevil, Iron Man, Captain America, and Thor. You may remember seeing ads in comic books for these figures, which had a selling price of $3.00 for all six!