Mussels near the sea.  
Image source, Theo Bosboom/Wildlife Photographer of the Year
Image caption,

Take a look at this sea of mussels! Did you know they bind together in this way to avoid being washed away from the shoreline?

The Bråsvellbreen glacier in Norway. 
Image source, Thomas Vijayan/Wildlife Photographer of the Year
Image caption,

This incredible image is of the Bråsvellbreen glacier in Norway. The glacier is part of Austfonna, which is Europe’s third largest ice cap. Some scientific research suggest glaciers like this one could disappear completely within 400 years due to climate change.

Lion and lioness. Image source, William Fortescue/Wildlife Photographer of the Year
Image caption,

This lion and lioness were snapped with an eerie backdrop of storm clouds lit by the setting sun in Tanzania's Serengeti National Park.

Pallas’s cat sitting with the moon in the bakground. 
Image source, Xingchao Zhu/Wildlife Photographer of the Year
Image caption,

This photograph of a Pallas’s cat was taken in Mongolia during the Lunar New Year. The animal's thick winter coat helps it survive at altitudes up to a whopping 5,000 metres!