What episode is dangerous flowers in Sailor Moon?

"Dangerous Flowers" is not the title of an episode in the original Sailor Moon anime. It's likely you're thinking of "The Flower of Evil", the second episode of Sailor Moon R.

In this episode, the villainous group, the Black Moon Clan, introduces the first of its many monstrous transformations: the flower-like "Wicked Flowers". These creatures are used to drain the life energy of humans, and Sailor Moon and her friends must battle them.

Let me know if you have any other questions about Sailor Moon!