I Need Help Finding A Costume For Halloween!?!!?

okay so i know we still have a while until halloween, but i need help finding a costume. so i want to match my boyfriend somehow, and he knows he’s going as the riddler from batman. he suggested that i go as another comic book charecter like batgirl, or cat woman, or poison ivy. But the problem is im not really into all that stuff, and i dnt know those charecters. So i need help. Please if u can give me a few suggestions on what i could be so it would somehow match the riddler. thanks soo much<3