Keen Senses. The Bog Rot Biter has advantage on Wisdom (Perception) checks that rely on sight, hearing, or smell.   Magic Resistance. The Bog Rot Biter has advantage on saving throws against spells and other magical effects.   Limited Telepathy. The Bog Rot Biter can magically communicate simple ideas, emotions, and images telepathically with any creature within 100 ft. of it that can understand a language.   Investment of the Chain Master   This creature's controller can use a bonus action to command it to attack.   This creature's weapon attacks are considered magical for the purpose of overcoming immunity and resistance to nonmagical attacks.   If this creature forces a creature to make a saving throw, it uses its controller's spell save DC.   When this creature takes damage, its controller can use their reaction to grant it resistance against that damage.