This is the amazing moment a heroic hippo saved a gnu from certain death. After being bitten by a crocodile, the large antelope is seen being dragged slowly under the water. But in a miraculous turn of events, a nearby hippo is seen making its way across the water to help the animal in its hour of need. Photo: One of the biggest hippos protects the gnu as it makes its way back to the shoreline, guarding it from any further attacks. (Photo by Vadim Onishchenko/Caters News)

A person poses on the track during a fashion competition at the Durban July horse racing event in Durban, South Africa, July 2, 2016. (Photo by Rogan Ward/Reuters)

A dog poses in traditional Chinese dress on Yaowarat Road in Chinatown on the eve of Lunar New Year on January 20, 2023 in Bangkok, Thailand. The Chinese diaspora of Southeast Asia is celebrating a lively Lunar New Year as COVID-19 restrictions have been removed. It is traditionally a time for people to meet their relatives and take part in celebrations with families. In Thailand, which has a sizeable population of Chinese lineage, people gather with family and celebrate with feasts and visits to temples. (Photo by Lauren DeCicca/Getty Images)

A soldier poses with a Hythe Mk III Gun Camera during training activities at Ellington Field, Houston, Texas in April of 1918. The Mk III, built to match the size, handling, and weight of a Lewis Gun, was used to train aerial gunners, recording a photograph when the trigger was pulled, for later review, when an instructor could coach trainees on better aiming strategies. (Photo by Harry Kidd/WWI Army Signal Corps Photograph Collection via The Atlantic)

A young man looks over his shoulder as men watching a soccer match in a nearby bar ask why he isn't watching the game, while walking with his date during the men's gold medal soccer match between Brazil and Germany during Rio 2016 on Saturday, August 20, 2016. (Photo by Aaron Ontiveroz/The Denver Post)

A fan of Colombia wears a tiger costume prior to the FIFA Women's World Cup Australia & New Zealand 2023 Group H match between Germany and Colombia at Sydney Football Stadium on July 30, 2023 in Sydney, Australia. (Photo by Justin Setterfield/Getty Images)

Google has built its first self-driving car prototypes and hopes to test hundreds more models this summer. If all goes well, the company is planning a pilot program in California over the next few years.