Pony is proud to be a greaser in the rumble because he is fighting alongside his friends and brothers.
Being a greaser gives Pony a sense of identity. Although he does not like the rumble and is nervous about fighting, and does not want to fight, he cares about his brothers and wants to stick up for his friends. He also respects his brothers and friends.
… I had put on more hair oil than was necessary, but we wanted to show that we were greasers. Tonight we could be proud of it. Greasers may not have much, but they have a rep. (Ch. 9)
Pony knows that he will be identifiable as a greaser with the greasy hair, and he wants the Socs to know he is a greaser. He wants them to know him and fear him. He fears more confident as part of a group, especially with his tougher friends. Pony is not much of a fighter, though he has proven himself in a fight, and he does not feel confident. He is relying on the gang mentality and the feeling of belonging.
Even though he does not want to fight, Pony knows that this rumble is necessary, or is at least seen as necessary by enough members of the Socs gang that it will happen one way or another. He does not to be left out. He has had a funny feeling about it. He does not like violence, and he has seen too much of it. Although he is intelligent enough, and sensitive enough, to be above the whole thing, he cannot step away from his roots and the people he cares about.
Pony is caught up in circumstances he can’t control. While he doesn’t like the gang violence, the greasers are still his friends and family. He depends on them, respects them, and counts on them.