A character who becomes a lycanthrope retains his or her statistics except as specified by lycanthrope type. The character gains the lycanthrope’s speeds in nonhumanoid form, damage immunities, traits, and actions that don’t involve equipment. The character is proficient with the lycanthrope’s natural attacks, such as its bite or claws, which deal damage as shown in the lycanthrope’s statistics. The character can’t speak while in animal form.

A non-lycanthrope humanoid hit by an attack that carries the curse of lycanthropy must succeed on a Constitution saving throw (DC 8 + the lycanthrope’s proficiency bonus + the lycanthrope’s Constitution modifier) or be cursed. If the character embraces the curse, his or her alignment becomes the one defined for the lycanthrope. The DM is free to decide that a change in alignment places the character under DM control until the curse of lycanthropy is removed.

The following information applies to this specific lycanthrope.

Wererat. The character gains a Dexterity of 15 if his or her score isn’t already higher. Attack and damage rolls for the bite are based on whichever is higher of the character's Strength and Dexterity.You gain the following abilities:

• Shapechanger. The wererat can use its action to polymorph into a rat-humanoid hybrid or into a giant rat, or back into its true form, which is humanoid. Its statistics, other than its size, 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.
• Multiattack (Humanoid or Hybrid Form Only). The wererat makes two attacks, only one of which can be a bite.
• Keen Smell.The wererat has advantage on Wisdom (Perception) checks that rely on smell.
• Bite (Rat or Hybrid Form Only). 1d4+ Dex/Str piercing damage.