5 times a contracted wrestler appeared for a rival wrestling company

#4 Christian Cage Appears At Slammiversary - 2012

An instantly classic moment

As mentioned in the aforementioned entry, then TNA star Ric Flair was allowed to accept his second WWE Hall of Fame induction by way of WWE and TNA coming to a secret agreement.

It took almost three months, but in July 2012, TNA's portion of the agreement was finally revealed. In a surprising move, WWE allowed the then reigning WWE Intercontinental Champion Christian to appear at the Slammiversary pay-per-view to reveal what was voted as the all-time greatest moment in TNA history. Christian, of course, had previously wrestled for TNA from 2005 - 2008 as Christian Cage, where he was a bonafide main event player and two time NWA World Heavyweight Champion.

The really interesting thing to come out of all this was revealed by Bruce Prichard on an episode of his 'Something To Wrestle With' podcast. Prichard claimed that when negotiating an appearance, he was told they could ask for anyone to show up at Slammiversary, with the exception of The Rock and John Cena. Which means TNA could have at least tried (but probably unsuccessful) to ask for the likes of The Undertaker, or Triple H, or another huge name to make an appearance.

Prichard would then claim that Dixie Carter chose it to be Christian because of his history with TNA, as well as because she enjoyed talking to him about cats.