Music themed homecoming... metal? slogan HELP!?

Every year for homecoming our school votes on a theme.... this year it was types of music. On the day of the homecoming football game, each cl builds a float to go into the homecoming parade. This float must be themed. We are sopres so we will get to vote 3rd. This means "rock" music will probably be taken. I was thinking about doing metal.... but i have to propose the idea so the cl officers will agree to it. We have to make a slogan to go with our theme and our football team. I was thinking about something like metal- "we're tough as steel... completely invincible" But i don't know that's why i need help!