Meet Molalla: Baby river otter Molalla, or Mo for short, is gently picked up by Julie Christie, the senior North America keeper at the Oregon Zoo, Friday in Portland. Molalla weighs about 2.5 pounds and was born Jan. 28. Zoo workers try to weigh the river otter when they can but have to be fast and sneaky. When the mother leaves to take a dip in the water, zoo workers quickly shut the door and take Mo out to be weighed and then put him back in the nest.