Pulling a Haha is defined as simply stealing and hiding someones belongings at work. Be wary, and only do this to friends. The said stolen object isnot destroyed, only hidden. The complete the Haha, one must leave a note, somehow, using whatever means possible. The note must say "Haha" and "Haha" only. Leave the note in the exact location of where said stolen item was and walk up to your friend and say "Haha" and walk away. The Haha reaches it's climax when the party who'se item was haha-ed goes to retrieve their item and screams, or yells, or reacts by loudly calling your name.
Josh to Troy-- "I'm just pulling a Haha on Jen."
Josh to Jen-- "Haha."
Troy to Jen-- Jen, go ahead and go home.
Jen (walking back to her keys screams)-- "JOSH!!!"