Grimlore's Grimoire
4-level Conjuration
You conjure a huge swarm of rats in any location you can see within range. The swarm dies when it drops to 0 hit points. The swarm is friendly to you and your companions. Roll initiative for the swarm, which has its own turns. It obeys any verbal commands that you issue to it (no action required by you). If you don't issue any commands, the swarm will spend its turn seeking out the nearest source of food. If a swarm is alive after 8 hours, you will lose your control over it and the swarm will disband into an appropriate number of tiny rats. You can recast the spell before it expires to regain control over the swarm again. The DM has the swarms' statistics (swarm of rats with 216 hit points).