Animal Companion
Animal Companions are spirits of the forest that manifest in physical form in order to assist and protect allies: specifically characters from the Ranger class. While Animal Companions do not typically speak, they can understand verbal commands and communicate empathically with the character they are bound to. Unless otherwise commanded, an animal companion will act in the best interest of their allies or nature itself.
Animal Companions will come and go according to their whim, but always appear when needed (appearing from around a corner or from the brush). The Animal Companion has a level equal to the character they are bound to and its own Hitpoints, Attacks, Defenses, Skills, and Movement. Similar to Simple Monsters, they always fail their initial saving throw.
In combat, your Animal Companion does not take initiative and instead acts when directed by you. Once per round you can command it as an Immediate Action to move its speed and also one of the following options: use one of its Innate Abilities, move a second time, or automatically save against a single effect that a save can end. You must pay any costs associated with the Companion's action. Additionally, certain Techniques (particularly those in the Hunter Discipline) allow you and your companion to act in concert. Some of these Techniques use up your Animal Companion's action for the round, as stated in the power. Animal Companions Threaten the area around them as normal, allowing them to Flank and take Opportunity Actions. These Opportunity Actions are in addition to the once per round action it may already take and are limited to three times per round (as any normal creature).
The Animal Companion is immune to Morale Damage and abilities with the Mind-Affecting keyword. If an Animal Companion is Dazed, Stunned, or suffers Energy Damage, it cannot use its Action for one round (either the current round if it hasn't yet acted, or the next round if it has). An animal companion does not count as a Summoned Creature for powers and abilities that affect them and can enter areas of Antimagic.
Animal Companions do not die, since they are manifestations of the spirit of the forest itself. Instead, if an Animal Companion is reduced to 0 Hitpoints, it simply runs away (back into the forest) or discorporates and disappears. After a Short Rest the animal companion will have recovered from its wounds and will return the next time that it is needed.