Bear

The Bear (Russian: Медведица, literally "she-bear"), once referred to in the development cycle as the Forest God, is an individual, large mutated bear that serves as the final boss-entity in Metro: Last Light. A ferocious and extremely territorial creature, the bear also displays remarkable levels of intelligence, to the point where it can empathize with humans. The bear returns in Metro Exodus as the apex predator in the Valley, and is referred to as the "Forest Master" (Russian: Хозяин Леса).

Overview
Bears appear to have mutated comparatively little after the Great War, as they retain their overall body shape, which is relatively similar to a pre-war specimen, behavioral characteristics, and even vocalizations. This is probably due to a lack of evolutionary necessity; pre-war bears could dwarf nosalises and watchmen in sheer size and strength. Though the specimens observed in the Gardens are far larger, this isn't unusual; many other surviving animal species are several times larger than their pre-war progenitors. As bears are omnivores, it is also not surprising that the species has adapted quite easily to its new environment, despite the fact that many of its previous food sources have become extinct or mutated beyond recognition and edibility.

Appearance
The mother bear is monstrously large even for the largest species of pre-war bears. It doesn't appear to have any fur left on most of its body, which further complicates identifying which species of bear it mutated from. The bear's incredibly long teeth jut out of its jaw almost at random, while its eyes and part of its mouth are bioluminescent. Also, its ribcage is partially visible through its skin. It appears to have no ears and the fifth claw on each of its paws almost appears to function as an opposable thumb. Bears are also present in the wilderness of Metro Exodus, and appear to be equally as mutated as their city-dwelling brethren (albeit with more fur and no visible tumors), despite other forest animals not being as affected by radiation. It's possible that, due to bears being omnivores and scavengers, they ventured into the cities after the war in search of food, and were thus more affected by radiation than other forest animals. The bear in Metro Exodus is referred to as the "Forest Master", and appears to be even larger than the mother bear, probably due to being a male.

Habitat
The bear is a surface living mutant, most likely because the Metro tunnels don't have enough food or moving space to support such a large predator. Bears are also encountered in forests and small towns all over Russia.

Metro: Last Light
As soon as Artyom climbs the great gate of the level, "Garden", the Dark One makes note that "there is something strange [nearby]". Throughout the game, hints to the bear's existence have been marked by trees swaying to the sound of heavy footsteps and intermittent roars. When finally encountered, Artyom will notice that the fearsome creature is hostile and a foe to behold.

The bear appears to be the mortal enemy of watchmen; the two of which seemingly feed off one another.

While the bear attacks Artyom and the watchmen, as the baby Dark One elaborates on, it does so as a mother in defense of the several mutant bear cubs seen previously in the garden. Taking on two distinct enemies at once, however, proved to be its undoing. While harmed little by Artyom's gunfire or the attacks of the watchmen, the creature could not focus on handling both at once. When down, the watchmen can distract the beast by clawing at it, and making it rise up into the air, giving Artyom the chance to make his way around behind it, and attack the bear's previously well-protected back. When the bear is defeated, it runs away from Artyom and gets swarmed by watchmen, with its cubs only able to look on helplessly. If Artyom just stares at it or walks away, the bear is killed and eaten by the watchmen - a sign of lingering contempt or apathy and a detriment to the player's moral points. Conversely, the player can decide to kill the watchmen for positive moral points and an achievement, after which the bear will stare at Artyom and run off with her cubs, seemingly deciding he is no longer a threat.

Tactics
Despite its massive size and considerable strength and speed, the bear is neither unstoppable nor extraordinarily dangerous. Though virtually immune to gunfire (or at least to the types of firearms Artyom has access to, since contemporary bears require powerful, large-caliber weapons to be brought down reliably), the bear's attempts to attack Artyom are rather sluggish, and easily avoided. This may be explained by the extent of the wounds on its back, where large portions of its flesh and fur are missing, leaving the spine exposed. Any attacks to this particular area will cause immense pain and temporarily incapacitate the beast. The bear will always attempt to chase Artyom; the Claymore is very useful for slowing it down, as the bear is not smart enough to bypass it.

Metro Exodus
The Bear returns in Metro Exodus, and appears as the apex predator of the Valley and the final boss of the map. In game, it is referred to as the "Forest Master". It causes a land slide that derails Alyosha and Artyom's railcar. It is first seen chasing off a pack of wolves, and is lurking in the forest as Artyom sneaks through it. When Artyom is caught in a trap set by the Children, the bear sneaks up them while they are arguing about what to do with Artyom. The bear killed one of the Children and fatally wounded another, but runs off due to being set on fire. It returns when Artyom arrives to the church where he was told Alyosha would be. After a lengthy battle, the bear runs off. When Artyom is finally reunited with Alyosha, the bear attacks Artyom after he falls into a ravine. Alyosha throws a Molotov cocktail at it, distracting it long enough for Artyom to escape from its reach. The bear also attacks Alyosha, forcing him to retreat. Still on fire, the bear thrashes around and knocks over a church tower, before turning its attention towards Artyom. Despite Artyom's best efforts, the bear ultimately prevails and almost kills him. The cliff edge gives way under the bear's weight, however, causing it to lose its footing and go over, while pulling Artyom with it. Both manage to hold on to the edge, with the bear trying to swipe at Artyom from below. With that, Artyom delivers a final blow by stabbing the bear in the eye with his knife, causing the bear to finally lose its grip and plunge to its death on the rocks below.

Tactics
The bear is a much more dangerous foe than in the previous game, since it can now charge through any obstacle in its path, be it a tombstone or a house. These will not slow the bear down in the slightest, so one has to be very mindful of their surroundings when avoiding the bear's charge, or else risk getting caught up on the world geometry. One would also be advised to keep a considerable distance from the bear, since it will usually telegraph its charge by standing on its hind legs, making it easier to avoid. If Artyom is close to the bear, however, it can charge without warning. Unlike the Mother Bear, the Forest Master has no weak spots and is able to shrug off excessive damage. It will often take most of Artyom's arsenal to make it retreat. Its biggest weakness is fire, and molotov cocktails are the most effective weapons against the bear, since they are able to stop it dead in its tracks and cause the bear to frantically try to put itself out by rolling on the ground, giving Artyom a few free shots.

Metro: Last Light

 * According to concept art made by a modeler of Last Light, the bear was at one point in development referred to as the Forest God.
 * It appears that the bear may either feast upon or have territorial conflicts with shrimp, more specifically, bog shrimps - a dead one is seen earlier in the level, decapitated. As it has not been eaten, this may imply that it was killed in territory competition instead of predatory behavior, or that the bear was interrupted before it could consume its kill, either by Watchmen or Artyom.
 * The most common bear in Russia is the brown bear, so this bear is likely mutated from one of these. It's unknown how the bear survived the Great War of 2013 though.
 * Bears only live to be around 25 years in the wild, with the oldest recorded at 37 years old, so it is unlikely this bear was born before the war and mutated during it. The radiation, however, could have given it greater longevity.
 * It's possible that the bear (or its ancestors) originated in the Moscow Zoo and has been living in the ruins ever since. The real life Moscow Zoo does contain brown bears, so this is likely. This also lends credence to the fact that other exotic species may have mutated and joined the post-apocalyptic fauna.
 * The bear cub's roars are slightly distorted roars of real-life bear cubs.
 * Said bear cubs also seem to be much less mutated than the mother bear. Their teeth and maw are not as crooked as the mother, and they sport fewer tumors and muscles, though all this might change as they grow older. It must also be noted that these bear cubs act relatively normal by pre-war standards: despite being obviously larger than present-day bear cubs, these juveniles act much like them. The cubs will play around with objects (in this case rolling a barrel around) and call for their mother when threatened.