These figures are about 1.5 inches tall, brightly painted, and are made of a hard solid plastic. I would come to learn years later that these are actually bootlegs of Japanese keshi figures. Apparently it's a tradition in Japan to release small scale toys of popular franchises, often sold in gachapon vending machines (which is what they call capsule machines that sell toys instead of candy in Japan.) The word "gachapon" comes from the sound effect the capsule makes as it falls after you put the quarter in.
Anyway, apparently these figures are actually bootleg recasts from figures that were made for a Godzilla board game in Japan. The figures came in multiple colors, as I have both a red and yellow Titanosaurus. There are Showa and Heisei versions of Godzilla. I know there also exists a King Cesar figure in addition to the ones I have. Also it appears the line may have been expanded a bit, as it also contains a Gamera figure, and a bipedal, winged dinosaur kaiju that could possibly be an Ultraman figure. There is also a smaller version of this winged figure that has a stamp built into it's base, which tells me there are probably other "stamp figures" of this type.
All the figures in my personal collection.
Close ups of Godzilla (showa,) Baragon, and Titanosaurs.
Close up of the unknown gliding dinosaur kaiju, and Gamera.
King Ghidora, Hedorah, Godzilla (heisei,) and Megalon. To the left is the small "stamp" figure.
Hedorah, Megalon, and Mechagodzilla
Close up of Gamera, and Mechagodzilla
A better shot of King Ghidorha
Godzilla (heisei,) and yellow Titanosaurus