Pokémon Brilliant Diamond and Shining Pearl feature 493 Pokémon and while most evolve typically through leveling up, a few have specific requirements before they can evolve. Some Pokémon require learning a particular move first, and one of those is Tangela which evolves into Tangrowth.
To get Tangrowth in Pokémon Brilliant Diamond and Shining Pearl, you will need to teach Tangela the move Ancient Power. Once Tangela knows this move and levels up, it will evolve into Tangrowth. Tangela learns Ancient Power at level 24. If you want Tangrowth, make sure your Tangela learns this move!
Tangela and Tangrowth are grass-type Pokémon. Tangela can be found after getting the National Pokédex. Its location is the Swampy Cave and Bogsunk Cave in the Grand Underground. If you want a Tangela before this point, you will need to trade for it.
Tangrowth has very scores in the HP, attack, defense, and special attack stats meaning it can fit a variety of roles. If you aren't interested in adding this Pokémon to your team, you will need it to complete your Pokédex.
For more information on Pokémon, check out How to get Ambipom in Pokémon Brilliant Diamond and Shining Pearl and How to get the National Pokédex in Pokémon Brilliant Diamond and Shining Pearl on Pro Game Guides.
Justin has been diving into fantasy worlds since he can remember. He is a certified nerd who has a deep love of reading, writing, and hiking. He has been writing since his college days, but specifically in gaming for two years. His favorite games are The Legend of Zelda, Pokémon, Hollow Knight, Celeste, and Banjo Kazooie.