The creature can’t take actions.
     The creature grants combat advantage.
     The creature can’t flank.

Normally a creature is subjected to this condition only during a surprise round, at the end of which the condition ends.

Published in Player's Handbook, page(s) 277, Player's Handbook 3, page(s) 223, Rules Compendium, page(s) 234, Monster Vault: Threats to the Nentir Vale, page(s) 125.