Gas

Gas is an animated short, directed by Chuck Jones and first released in May 1944. It features Private Snafu learning the value of a gas mask in warfare. The cartoon was produced by Warner Bros. Cartoons. The script writers for the Snafu cartoons were typically uncredited, though animation historians consider that several of them were written or co-written by Dr. Seuss and Munro Leaf.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.