It's in the compendium, Acrobatics.
HOP DOWN
Make an Acrobatics check to hop down 10 feet and land standing.
Action: The check is usually part of a move action, but it can be part of any of the creature’s actions that involve the creature moving.
DC: DC 15. The creature can make this Acrobatics check only if the drop is no more than 10 feet.
Success: The creature hops down, lands standing, and takes no falling damage. The downward move uses no movement from the action.
Failure: The creature falls.