Answer:
I'm an animal. I love marching. I always wear a tuxedo. What am I?
I help engines spin and pants stay up.
I am black within and red without With four corners round about.
I'm as simple as a circle worthless as a leader; but when I follow a group their strength increases tenfold. By myself I'm practically nothing.
I run up and down the stairs without moving. What am I?
When is it bad luck to see a black cat?