Interesting Day - Wondering About a Halloween Costume

So I was at school today and because I get off early on Fridays, it gave me time to come home for a nice nap.
Throughout the day, I was thinking about a nice Halloween costume for the year. My friends have all said that they will be dressing up as Pikachu`s but then I don`t want to do that.
My ideas for a Halloween costume this year is either a Starcraft Terran Marine, or a One Piece character (both of these ideas are due to me being an intense fan of both).
Getting a One Piece costume shouldn`t be too difficult, but I`m not sure if majority of the population at my school will know what I`m dressing up as... Which would be pretty sad. However, for the Marine costume, I`m sure everyone would know what I am dressing up as but I am not rich so I`d have to use cardboard to make it. It is for this reason that I am leaning away from the idea of a Marine costume because if it rains.... I can say bye to my beautiful suit :(

Since I am on the topic of these costumes, I`d like mention Atelier Fantastic` Art`s marine costume below.

If only I had the skills to make such a beautiful masterpiece... But to all the ONE PIECE fans out there... I will probably dress up as a One Piece character instead. I was really hoping to get intensely buff so I can go to school shirtless with a symbol of the Whitebeard Pirates on my back to *Spoiler Alert* remember our fallen heroes: Portgas D. Ace and the almighty Whitebeard (Edward Newgate).