WOSO Gang

When WOSO Gang enters the battlefield, you may pay any amount of {u}. If you do, create that many tokens that are copies of WOSO Gang, and put them on the battlefield.
Whenever WOSO Gang attacks, you may pay {u}. If you do, you may draw a card for each card named WOSO Gang that is attacking.
Strength in numbers, right? I read it in a large book, so it must be true.