A group of otters can be called by different collective nouns, depending on the context. Here are some of the most common ones:

• Bevy: This is a general term for a group of animals, and it can be used to describe a group of otters.

• Family: Otters are social creatures that often live in family groups consisting of a mating pair and their offspring. Therefore, a group of otters can also be called a family.

• Lodge: This term is less common but still used to describe a group of otters.

• Romp: This term is used to describe a group of otters playing or frolicking together.

• Raft: This term is used to describe a group of resting otters floating together on their backs.

Its worth noting that some of these terms are more commonly used than others, and some are more specific to certain behaviors or contexts. For example, "romp" is often used to describe playful behavior, while "raft" is used to describe resting behavior. Additionally, some sources, such as Reddit, have suggested more creative collective nouns, such as "puddle" for a group of otters cuddled together. However, these terms are not widely recognized or used.