Samurai Jack - Season 4 Episode 2 -

Jack enters the abandoned city of Andromeda and finds himself under attack by a monstrous giant robot, the Mondo-Bot. Jack is initially defeated and rescued by local robots who believe he is the Chosen One. The city is built on a magical city of giants and Jack goes underwater to seek them out and finds a giant samurai robot which pulls Jack into it. Jack's bot is resistant to everything the Mondo-Bot shoots at it so the two engage in an enormous close combat battle and Jack proves triumphant.