Near rhymes:
* Hilarious
* Various
* Curious
* Acrimonious
* Mysterious
Eye rhymes:
* Marigolds
* Barricades
* Parades
Slant rhymes:
* Aquarius (similar vowel sound)
* Taurus (similar vowel sound)
Ultimately, the best rhyme for "Sagittarius" depends on the context and desired effect.