This is the first episode since season 1 to feature Ashley Boyd (Cinderella).
When Emma talks to Elsa about reading Elvish, she says that she hasn't even seen "Lord of the Rings." The voice of Grand Pabbie, John Rhys-Davies, was in The Lord of the Rings: The Fellowship of the Ring (2001) as a Dwarf named Gimli.
Cinderella gave birth to her baby in season 1 (2011). Her baby should be a toddler, not a baby as seen during their mommy-and-me session, indicating that she has a second child, which would explain why she's the one leading the class.