What animal is combined with ladders in the popular board game?

Snakes and ladders is a board game for two or more players regarded today as a worldwide classic. The game originated in ancient India as Moksha Patam. It is played on a game board with numbered, gridded squares. A number of "ladders" and "snakes" are pictured on the board, each connecting two specific board squares. The object of the game is to navigate one's game piece, according to dice rolls, from the start (bottom square) to the finish (top square), helped by climbing ladders but hindered by falling down snakes.

Source: Wikipedia