Chinstrap penguins are successful in Antarctica because they catch prey by pursuit-diving using their flippers to ‘fly’ through the water. Their stomachs adapted to the ice by becoming softer to slide farther distances.
The Crabeater Seal has an adaption to slither over land fairly well and they range farther onto continental Antarctica. Crabeater seals have specialized krill-filtering cusps on their teeth to trap their prey.
The emperor penguin has adapted its coat to four layers of scale-like feathers protect them from icy winds and provide a waterproof coat. They also are successful because on the ice masses, they use strong claws on their feet to help grip the surface as they shuffle.