Futurama Episodes

Dr. Zoidberg is accused of flag desecration when, at a Washington D.C. celebration, he cannot restrain himself from eating a large flag. After Zoidberg is sentenced to death, his people send an invasion force to enslave the people of Earth and teach them the meaning of freedom.
wikipedia.org summary:
When Zoidberg publicly devours an Earth flag, he is sentenced to death for his anarchic behavior. Before the sentence can be carried out, the Decapodians come to Zoidberg’s aid by invading Earth, teaching the populace the true meaning of freedom.
imdb.com summary:
Dr. Zoidberg’s exuberant celebration of Freedom Day makes him Public Enemy #1.