Diabolize

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards. Then if you sacrificed a creature
with power 3 or greater this way, incubate 4.
(Create an Incubator token with three +1/+1
counters on it and "{2}: Transform this artifact." It
transforms into a 0/0 Phyrexian artifact creature.)
"Her name? Named after the lethal spider. Atraxa."
—Jin-Gitaxias, to Elesh Norn