I have a 960x960 spritesheet with each tile being 192x192. I initialized my spritesheet and animation like so: spritesheet = new SpriteSheet("resources/spritesheets/player.png", 192, 192); walkingLeft = new Animation(spritesheet, 3, 0, 0, 1, true, 20, true); When I attempt to render the animation, I get a java.lang.ArrayIndexOutOfBoundsException: -1 error. This error doesn't occur when I'm creating an animation from images in the same row. Therefore, I'm assuming that the error is being caused because of the way Slick is handling horizontal scanning (going to the next row after reaching the end).