An allusion is uded to make a reference to a place, thing, person, or idea which contain certain cultural value. If an allusion doesn't make reference to something of cultural relevance nobody would be able to understand it, therefore it won't commit it's purpose.
In this case Anthony points out the evilness of his pal Scott. He makes allusion to Gru, the protagonist of the movie "Despicable Me". Gru is a supervillain who wants to steel the moon and makes an elaborate plan to do it. Gru haves a great time doing evil things through his day, by carring out his detailed and evil plan, Scott resembles a supervillain.