Certain levels are also populated by hazards that must be avoided or removed. For example, some levels contain algae that will absorb water and grow. Other types of fluids will sometimes appear, such as purple poison/acid, reddish mud, and green ooze/slime. If either poison, ooze or mud reaches the inlet, the level is failed and must be restarted. (Swampy jumps out of the tub if poison/acid enters it, but simply gets surprised or disgusted if ooze/slime or mud enters it instead). If all the water or any fluids that must be converted disappear etc., Swampy cries mournfully as the level restarts too. (only on the free version.) The poison, mud, and the ooze will kill all the rubber ducks (the ducks turn into skulls and make a painful-sounding quack) on contact.