How do you get the red scale in Pokemon HeartGold?

You can get the Red Scale in Pokemon HeartGold by defeating the Legendary Pokemon, Groudon.

Here's how to obtain Groudon:

1. Obtain the Red Orb: This item is needed to summon Groudon. You can get it from the Seafloor Cavern in the Sevii Islands.

2. Travel to the Cave of Origin: This location is in the Sevii Islands, specifically on One Island.

3. Use the Red Orb: Once you are in the Cave of Origin, use the Red Orb to summon Groudon.

4. Battle and Capture Groudon: Prepare for a tough battle! Groudon is a powerful Pokemon, so make sure your team is well-prepared. After defeating it, you have a chance to catch it.

5. Groudon will drop the Red Scale: After you capture Groudon or faint it in battle, it will drop the Red Scale as an item.

Remember that the Red Scale is a rare item, so be sure to check your bag after defeating Groudon. Good luck!