All cats are animals. Some otters are not cats. Therefore, some otters are not animals. All black holes are entities that produce a tremendous amount of gravity. So, all entities that produce a tremendous amount of gravity are stars that have collapsed in on themselves.
All otters are mammals.
All otters are animals. So, all animals are mammals. Some highly improbably events are cases of winning a lottery. So, some cases of winning a lottery are miracles. Some animals are cats.