We are dealing with imaginary creatures and beings in Fantasy Literature, so don't expect that these resources actually agree in their descriptions of the creatures. After all, all of these creatures exist only in the minds of the persons reading or thinking about them.
This is only a short list of the fantasy books that are (mostly) available in the school library.
Atwater-Rhodes, Amelia. Hawksong: The Kiesha’Ra: Book One .
Constable, Kate. The Singer of All Songs: Book One, The Chanters of Tremaris Trilogy. Arthur A. Levine Books, Scholastic, Inc.
Farmer, Nancy. The
Delaney, Joseph. Revenge of the Witch, The Last Apprentice: Book One. Patrick Arrasmith, Illus. Greenwillow Books, Harper Collins Publishers.
Delaney, Joseph. Curse of the Bane, The Last Apprentice: Book Two. Patrick Arrasmith, Illus. Greenwillow Books, Harper Collins Publishers.
Avi.
Barron, T. A. The Ancient One. Tom Doherty Associates, Inc. New York. 1994. p. 339. ISBN 0-812-53654-1.
Barron, T. A. Heartlight. Tom Doherty Associates, Inc. New York. 1994. p. 272. ISBN 0-812-55170-2.
Barron, T. A. The Merlin Effect. Tom Doherty Associates, Inc. New York. 1996. p. 254. ISBN 0-812-55169-9.
Chant, Joy. Red Moon,
Garner, Alan. The Moon of Gomrath. William Collins and Son. London. 1972. p. 173. ISBN XX.
Garner, Alan. The Wierdstone of Brisingamen. William Collins and Son, Ltd.
Hunter, Mollie. Mermaid Summer. Harper and Row Publishers. New York. 1988. p. 118. ISBN 0-060-22628-5.
Jones, Diana Wynne. The Magicians of Caprona. Greenwillow Books, William Morrow & Co. New York. 1980. p. 223. ISBN 0-688-84283-6.
Levine, Gail Carson. Ella Enchanted. Publisher. Harper Collins. New York. 1997. p. 230. ISBN 0-060-27511-1.
Pierce, Tamora. Daja's Book: The Circle of Magic, Book
Pierce, Tamora. Emperor Mage: The Immortals, Book
Pierce, Tamora. Emperor Mage: The Immortals, Book
Pullman, Philip. Clockwork, or All Wound Up. Scholastic, Inc.
Rowling, J. K. Harry Potter and the Chamber of Secrets: Year Two. Scholastic, Inc.
Tomlinson, Theresa. The Forestwife. Orchard Books.
Voigt, Cynthia. Jackaroo. Atheneum.