Provided by The Denver ZooSloths Charlotte Greenie and Elliot hang around at the Denver Zoo’s Bird World. Grab your champagne: The Denver Zoo announced Wednesday that it is expecting a baby sloth. The sloth will be the first offspring of Charlotte and Elliot, who were matched as part of the Species Survival Plan, said zoo spokeswoman Marina Belisle. Sloths have a 10-month gestation period, she said.