Final Boss Help (Obvious Spoilers)?

I got to the fight with Bowser and fought until he spawns the Whomp and heals himself, and at that point I was pretty much done. I know the Whomp has to be taken out by scissors, but I had no way of knowing the prior to the battle, so I had to just die and retry (which is some pretty terrible game design). I want to finally finish this game, but I don't want to deal with how bad it is. Before I pick it back up, do I need any other Thing Stickers to complete the battle?