Cosplaying villains is so much fun, especially if you want to do it in character (although, not too in character). Generally I've found that if people say anything rude, it's towards the character (my Envy, for example, gets a lot of this) and they are trying to pull you into a probably short roleplay.
And even if you do find someone who is trying to be a jerk, Galactus is an awesome choice, and the good reactions will almost certainly outweigh the bad ones.
Now known as: LinaIsNotANoob
Wasp - Marvel Universe (100%), Winter Soldier - Marvel Universe (100%), Sasha - Attack on Titan (40%), Link (secret version) - Legend of Zelda (60%), Lady Loki - Marvel Universe (70%), Fem!Prussia - Hetalia (100%), Envy - Fullmetal Alchemist: Brotherhood (100%), Lily - Pandora Hearts (95% - converting from Zwei) and Pikachu - Pokemon (100%)