#1 The Undertaker
The Undertaker is arguably the greatest wrestling Superstar of all time, and his legend continues to grow every year -- 'Taker is still going strong in 2018 at the astonishing age of 53 years.
It's clear Vince McMahon has been relying on established veterans such as Kane, The Undertaker and Shawn Michaels to help draw in fans during these slow periods in WWE, but unfortunately, McMahon will be unable to rely on "The Deadman" to be at his "beck and call" for much longer -- The Undertaker is extremely close to that dreaded retirement.
Without question, The Undertaker's body is beginning to break down from the countless years spent inside the squared circle, and most fans would agree that Undertaker won't be able to wrestle for much longer. Despite seemingly "retiring" after WrestleMania 33, The Undertaker has since resurfaced in WWE many times, and he is currently set to go one-on-one against Triple H at the Super Show-Down in Melbourne, Australia this Saturday.
Although it's likely that The Undertaker will perform at next year's WrestleMania 35, it's highly probable that 'Taker will call it quits after 2019 -- fans will be left in tears when this day occurs...