Aggressiveness Level is the classification of behaviors of alien lifeforms.
Harmless: It is not completely dangerous.
Very Low: It could be not harmless, unless disturbed.
Low: It will attempt to scare if it was threatened.
Medium: It will have a chance to hurt if confused or threatened. Will attack if harmed or attacked.
High: It will attack and probably kill if threatened or confused.
Very High: It will attack to kill if something gets into its territory and will hurt severely.
Extreme: It will kill a life form on its sight.