Gintama Episode 42: You Know What Happens If You Pee on a Worm
Episode 42 of 201 of Gintama, aired February 7, 2007, 25 minutes. Available with English subtitles and dub where released.
Episode summary
Gintoki, along with Umibouzu, goes to combat the alien while at the same time avoiding the Shogunate's side of attack (on the alien).