You need the Bright Card if you want to get into the casino. You can get it from Knife Guy in Booster's tower. Work you way through his tower until you encounter Knife Guy. You will have to play many games of guess which hand the ball is in. After awhile he will give you the Bright Card. You may need talk to the man in the inn at Nimbus Land. If you read his card, it would say that to get to Grate guy's casino it would take three jumps and no chomps allowed. Go to the Bean Valley, and if you travel long enough, you will find a place where a Shy Away is watering some plants. Wait for it to water one and fight. Go into the pipe after it has been defeated. Do this until you are in a room where a Gold Chomp is in the corner. Defeat it and go to the very corner of the left side of the room. Jump three times. You should hear a noise for every jump. After the third jump a yellow stand should appear. Jump on it and leave the room. You should now be right in front of the casino. You are now free to play with the slots and blackjack. You get a frog coin every time you win, which is a good way to get them.