So, to understand the "joke" we need to go back to this week's RAW when WWE commentator JBL was talking about The Undertaker and his legacy. He mentioned that Undertaker had won his first WWE Championship back in 1991. He said that Taker won his first of 7 titles from "the immortal one" rather than using Hulk Hogan's name.
Not only has Hogan been removed from WWE Hall of Fame website and rarely to be found on the WWE Network, but the organization is also doing all they can to keep his name off of programming, which gets us back to JBL referring to him as "the immortal one."
Hulk Hogan took notice of this and had some fun with it in a couple tweets this week:
OK Maniacs great day on North Beach, chest and back day tomorrow , "The IMMORTAL One" is tired ,only love 4ULoyality4Life. HH— Hulk Hogan (@HulkHogan) November 23, 2015
Congrats Sheamus on winning the WWE TITLE!!!! "The IMMORTAL One". HH— Hulk Hogan (@HulkHogan) November 23, 2015