You're probably familiar with the anatomical illustrations of Godzilla and his pals, but have you ever seen these cross-sections of Gamera and his buddies? Check out eyelids that eject shurikens and dorsal spikes that shoot rainbows.
Over at Pink Tentacle, there's a great round-up of Daiei Motion Picture's kaiju anatomy. For example, Barugon's (above) accoutrements include "dorsal spikes that produce a deadly rainbow ray," a "30-meter-long weaponized tongue, "a stomach that can digest diamonds (his favorite food), and radar horns atop his head." Radar horns! Of course!
Guiron over here comes equipped with a head "100 times harder than diamond and [that's] packed with shuriken-like stars that can be fired from a pair of openings above the eyes." He also has 60 times more teeth than a piranha, but the illustration shows maybe 12. This is highly enlightening, as I always assumed the leathery hides of kaiju hid extremely sweaty actors.