Large clock hands are those that are longer than around seven inches (talking the minute hand, not the hr hand). The reason big clock hands are so marked is that lengths more than that cutoff size consider way too much for a typical electric motor to turn. In other words, the typical torque wants, calling for the designer of the wrist watch to order a high-torque movement instead.
Huge clock hands are in theory endless in size, but virtually talking you won't see any type of longer than eighteen inches, meaning that the corresponding clock would certainly be at the very least a yard in diameter. Even after that, the likeliest application for such a watch would certainly be something placed straight to the wall surface (using the wall as the dial, so to speak) without being enclosed in a case.