Assume that I, as a 12th level cleric, cast this spell on my handy Jar O'Scorpions (tm). According to the SRD, this will create 3 Huge scorpions with 14ac and 34hp (average) that get one attack per round at +8/2d6+8.
Now, if I look up "Huge Scorpion" in the MM I see that these giant vermin...