Insanity Elementals are fast-moving enemies that only do damage to you by rolling into you, exploding, and killing themselves in the process. This explosion does a decent amount of damage, where you wouldn't want to get hit by multiple of these back-to-back. They do not have much health and will die relatively quickly; sitting in a corner and waiting for them to come to you is the best strategy to ensure you can always see them coming and have more than enough time to take them out before they reach you.