I am writing a story about 800+ words and i am doing fantasy. However i need 2 types of mythological creatures, the good one that lives in grassfields or a forest. Is a centaurs good?

And the bad one that is the evil enemy, nothing to huge. I was wondering if a satyr is good?

The Island of the ???? "Centaurs

The shaft of the arrow was black and fleched with crow feathers, but Hylas couldn't see the head because it was buried in his arm. Clutching it to stop it wobbling before it started internal bleeding, He scrambled down the slope. No time to pull it out. He had to hurry quick before the ??? "Satyr people captured him, arrows whistled past him as he sprinted down the cliff. His hand sprang into action to castle a spell towards the Satyr, this created a confusion allowing him to to safely take cover into the cave's mouth

Hylas's village wasnt far. He lived in a ??? (Forest or grassland)