The poor quality batteries that arrive already installed in electronic toys that you'd recieve on Christmas. Typically green and red, gold and red, or any combination of the three. And ususally weighing about half of what a duracell, or energizer would weigh. Toshiba is a common brand of Santa Claus batteries
person 1- Dude, did you get barreries for the digital camera?
person 2- Yeah man. They're those silver ones, ya know, the kind with the black cat jumping through the number nine.
person 1- Oh fuck! Those are like santa claus batteries. They don't even have the power to turn the camera on!