The three Golem Girls are Jin, Brandi, and Bud, the separated components of the Chimera, an ancient weapon of mass destruction. Monica met them when Tepoz teleported them in; she was unimpressed with his ability to summon drunken college girls to her apartment. They soon sobered up and have been finding their own way in modern Minneapolis.
While they pass for human, occasional signs of their nature come up. All of them can shapechange into an iconic animal (lion, goat and snake), and have characteristically dramatic teeth. (Tina also shows the same dentation, and gave an unconvincing explanation of why.) Jin occasionally shows snakelike eyes. Bud has a large hatch in her abdomen, accessing an extradimensional space, but this is invisible when closed.
All three have the ability to teleport - "poit" - are indestructible and possess superhuman strength. They have shown various forms energy projection such as breathing fire and can shine light from their eyes, mouths, and/or faces - in the latter mode they each show a characteristic glyph. Tepoz said that "Once separated they were more controllable but still every bit as dangerous" - not really a comforting thought when the Chimera already wiped out civilization once.
Pablo has admitted that it's no coincidence that the three drunken girls summoned by Tepoz, god of alcohol, are phonetically Gin, Brandy, and Bud.
Their first appearance was 4 Nov 2004.