Orangutangs, maybe. They nurse for an average of seven years before weaning.
The Bowhead whale is the longest living mammal.
Narwhal.
A giraffe is the tallest mammal alive, it also has the longest neck!
A giraffe is the tallest mammal alive, it also has the longest neck!
Whales.
snake
A Kangaroo
a dolphin or whale
a camel
The animal that takes the longest to be born is the African elephant. Their gestation period lasts about 22 months, which is the longest of any land mammal. After this extensive period, typically a single calf is born, although twins can occur on rare occasions. This prolonged gestation allows for the development of the elephant's large size and complex brain.
I'm not certain, but I'm pretty sure the Fin Whale, Balaenoptera Physalus, is the second longest mammal at about 88 feet long.
African elephants have the longest gestation periods, at around 22 months.