"The overwhelming urge to join a dance class where the end result is high velocity sweating and fatigue."
Once a witch/warlock casts the spell to zumbify you, you will be addicted to Zumba. (well, they couldn't name it ZOMBA, could they...even an idiot would have figured that one out.)
At the end of each class the spell caster will wait until the weakest soul collapses from exhaustion. At this point, the unsuspecting person will be "helped" to his/her car, never to be seen from again.....alive.
They will be seen however, in popular music videos because even in death, they continue to have the urge to dance.
this particular dance is so popular, they even have t shirts for members: