The spider snake is a chimerical creature known to inhabit the Earth Kingdom. Not much is known about the species, apart from the fact that rolling two fives while gambling is referred to as "spider snake eyes".
The conventional spider is an eight-legged, eight-eyed arachnid. The snake is a non-legged reptile. The phrase "spider snake eyes", which correlates to spinning a ten in dice games, is most likely a reference to how getting a total of two with both dice is dubbed "snake eyes".