* "Nutcracker" is usually associated with the ballet and the music. The ballet tells the story of Clara and her magical nutcracker, and the music is a very famous suite of pieces by Tchaikovsky.
* There isn't a single poem titled "Nutcracker". Some poets may have written poems inspired by the ballet or the story, but there's no standard, definitive poem with that title.
If you're thinking about the ballet, it's not a poem. It's a dance production, and the meter would be the rhythm of the music, which varies greatly across the different parts of the ballet.
If you can provide me with the specific poem you're asking about, I can help you figure out its meter.
Let me know the name of the poet and the text of the poem, and I'll be happy to analyze it for you!