Snake Eyes is a common parlance for a pair of 1s. When both of the dice rolled in Craps land on a 1, the outcome is commonly referred to “Snake Eyes”, as the two dots look like the beady eyes of a serpent. Similar slang terms are used for other kinds of pairings in Craps as well, like Loose Deuce for a 1 and a 2, Nina for any pairs that give the total sum of 9, and Yo for a 6 and a 5.