conjure siege engine

when you cast this spell, you create a large siege engine. this siege engine acts on its own, and is friendly towards you and your allies. when a siege engine is created, choose from the engines below. all of the siege engines have AC 16 and a HP of 30

catapult:+4 to hit, range 200 ft, 8d4 bludgeoning

battering ram:+3 to hit, range 10 ft, 4d6 bludgeoning

ballista:+2 to hit, range 150ft, 5d10 peircing