The Golden Age Blue Beetle first appeared in Mystery Men Comics #01, published by Fox Comics. His alter ego was Dan Garrett, the son of a Police Officer killed in the line of duty, who himself became a cop.
He originally fought against the Underworld without superpowers, however he had a bulletproof blue costume, made of chain-mail that was described as 'thin and light as silk but stronger than steel'. He also temporarily gained superhuman strength and increased stamina by taking Vitamin 2X.
He intimidated his opponents by leaving his signature scarab symbol where it could easily be found.
He had a side-kick for a short time called Sparkington J. Northrup, better known as 'Sparky'.
Other regular characters were, Joan Mason, a beautiful blonde reporter for 'The Daily Blade', Mike Mannigan, Dan's Irish partner on the force, who was convinced that the 'Blue Beetle' was a member of the criminal fraternity, and Dr. Franz who invented the bullet-proof and the Vitamin 2X formula, as well as many other useful gadgets to assist the 'Blue Beetle'.
The 'Blue Beetles' powers gradually increased, over time, including the ability to fly and x-ray vision, amongst other endowments. As Super-heroes fell out of favour during the late 1940's, his abilities were reduced, until all his super-human powers were removed. His adventures then became darker until eventually the character was put on hold.
Charlton Comics revived the character in the mid-fifties and DC Comics re-introduced the 'Blue Beetle' in the 1980's.