"Proc" stands for "Programmed Random OCcurance". It does not even vaguely apply to anything Magic cards do. Don't use it.
Level 1 Judge as of 09/26/2013
Zammm = Batman
"Ability words are flavor text for Melvins." -- Fallingman
Yes, unless the cost or effect explicitly asks you to sacrifice an untapped creature. (But I can't think of any that does.)
can i sacrifice a tapped creature btw?
Tax evasion is nothing but legitimate self-defense against the theft that is tax collection.