My Life as a Teenage Robot Easter Egg - El Tigre Billboard

In the episode "Samurai Vac" (pun on the Cartoon Network show "Samurai Jack"), during the scene when Samurai Vac is fighting the giant three-headed monsters a billboard in the background multiple times with the initials "E.T" can be seen above a picture of Manny Rivera from another Nick show called "El Tigre".