Students from St Andrews University are covered in foam as they take part in the traditional Raisin Weekend in the Lower College Lawn, at St Andrews in Scotland on October 22, 2018. The “raisin weekend” stems from a gift of raisins (now flour and foam) traditionally given by a first year student to their academic “parents” in gratitude for their guidance. (Photo by Russell Cheyne/Reuters)

A South Korean marine in action during their regular drill on Yeonpyeong Island, South Korea November 1, 2018. (Photo by Jeon Heon-Kyun/Pool via Reuters)

Cooler temperatures begin this week as a polar vortex brings much colder conditions with the chance of snow for Snowdonia, Ogwen Valley, North Wales on 22nd October 2018. The Ogwen Valley and Tryfan Mountain looking splendid in the Autumn sunrise. (Photo by DGDImages/Alamy Live News)

The Pink Floyd inflatable pig floats next to Broadcasting House to promote their new exhibition at the V&A museum, in London, Britain May 10, 2017. (Photo by Neil Hall/Reuters)

People play with foam at a water park in Yantai, Shandong province, China June 16, 2107. (Photo by Reuters/Stringer)

A worker lifts up tiles during a bodybuilding contest for tile factory workers as part of celebrating Indonesia Independence day at Jatiwangi village in Majalengka, Indonesia West Java province, August 11, 2017. Indonesia Independence day is on August 17, 2017. (Photo by Reuters/Beawiharta)

Revellers enjoy themselves during Hogmanay celebrations in Edinburgh, Scotland on December 31, 2017. (Photo by Russell Cheyne/Reuters)

A fox runs out onto the pitch before the start of the second half. Celtic League 2012/13, Round 19, Leinster v Ulster, RDS, Ballsbridge, Dublin, March 30, 2013. (Photo by Paul Mohan)