Sources
CR
Type
Size
Alignment
Movement

Werebear

Medium Humanoid (human, shapechanger), Neutral Good

Armor Class 10 in humanoid form, 11 (natural armor) in bear or hybrid form
Hit Points 135 (18d8 + 54)
Speed 30 ft.
STR
19
+4
DEX
10
+0
CON
17
+3
INT
11
+0
WIS
12
+1
CHA
12
+1
Skills Perception +7
Damage Immunities bludgeoning, piercing, slashing, from nonmagical attacks that aren't silvered
Senses passive Perception 17
Languages Common (can't speak in bear form)
Challenge 5 (1,800 XP)

Traits

Shapechanger. The werebear can use its action to polymorph into a Large bear-humanoid hybrid or into a Large bear, or back into its true form, which is humanoid. Its statistics, other than its size and AC, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Keen Smell. The werebear has advantage on Wisdom (Perception) checks that rely on smell.

Actions

Multiattack. In bear form, the werebear makes two claw attacks. In humanoid form, it makes two greataxe attacks. In hybrid form, it can attack like a bear or a humanoid.

Bite (Bear or Hybrid Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit:15 (2d10 + 4) piercing damage. If the target is a humanoid, it must succeed on a DC 14 Constitution saving throw or be cursed with werebear lycanthropy.

Claw (Bear or Hybrid Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit:13 (2d8 + 4) slashing damage.

Greataxe (Humanoid or Hybrid Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit:10 (1d12 + 4) slashing damage.

Lore

One of the most ancient and feared of all curses, lycanthropy can transform the most civilized humanoid into a ravening beast. In its natural humanoid form, a creature cursed by lycanthropy appears as its normal self. Over time, however, many lycanthropes acquire features suggestive of their animal form. In that animal form, a lycanthrope resembles a powerful version of a normal animal. On close inspection, its eyes show a faint spark of unnatural intelligence and might glow red in the dark.