However, you can still obtain a Serperior in Diamond, but it will not be able to learn Frenzy Plant. Here are some ways to get a Serperior in Diamond:
* Trade: The easiest way is to trade for a Serperior from someone who has played Black or White.
* Breeding: You can breed a Snivy with another Pokémon that knows Frenzy Plant, but the offspring will only inherit the move if the parent is holding a Power Herb.
Remember, Serperior in Diamond will still be a powerful Pokémon, even without Frenzy Plant!