How can you get donphan on diamond?

You can't directly get Donphan in Pokémon Diamond. Donphan is a Pokémon that evolves from Phanpy, and Phanpy is not found in the wild in Pokémon Diamond.

However, you can obtain Donphan in Pokémon Diamond through trading. Here's how:

1. Find a friend or online trader: Look for someone who has a Phanpy or Donphan they are willing to trade.

2. Agree on a trade: Decide what Pokémon or items you're willing to offer in exchange for the Phanpy or Donphan.

3. Connect your systems: Use the Nintendo DS Wireless Adapter or the Nintendo Wi-Fi Connection to connect with your trading partner.

4. Initiate the trade: Once connected, access the Trade Center and initiate a trade.

5. Complete the trade: Exchange the Pokémon and enjoy your newly acquired Donphan!

Note: If you trade for a Phanpy, you'll need to level it up to level 25 to evolve it into Donphan.