* Exeggutor isn't native to the Sinnoh region. It is a Pokemon from the Kanto region, which is featured in Pokemon Red, Blue, and Yellow.
* You can trade for one. The easiest way to get an Exeggutor is by trading with someone who has one from a different generation game.
Here are some ways to get an Exeggutor in Diamond:
1. Trade with someone online or locally: Many players are willing to trade Pokemon from other generations. You can find trading partners on online forums, Discord servers, or in your local community.
2. Utilize the GTS (Global Trade System): Deposit a Pokemon you want to trade and search for an Exeggutor. Keep in mind, the GTS is unreliable and finding the specific Pokemon you want can be challenging.
Important Notes:
* Exeggutor evolves from Exeggcute, which can be found in the Grand Underground. However, it is still highly unlikely to find a wild Exeggutor in Diamond.
* Breeding: You can breed Exeggcute with other Pokemon to potentially get an egg that hatches into an Exeggutor. However, you'll need to have an Exeggutor from another game to start this process.
Let me know if you have any other Pokemon questions!