The Undertaker was one of WWE's top full-time stars in the 2000s before moving into a part-time role with the company in the 2010s. The Hall of Famer recently opened up about his experience working with Ken Anderson, aka Mr. Kennedy, on the SmackDown brand in 2006 and 2007.Mr. Kennedy defeated The Undertaker via disqualification at No Mercy 2006 before beating him again in a First Blood match at Survivor Series 2006. Later that year, The Deadman earned a victory over his rival in a Last Ride match at Armageddon.On the latest episode of Mic Check with Mr. Anderson, The Undertaker only had positive things to say about his feud with the former WWE star:"For me, personally, I loved working with guys with that [height difference] story to be told, but the one thing that has to happen is my opponent has to be ultra aggressive. Not only the incredible personality that Ken had, but that has to be there to pay it all off, and he had that." [From 04:42 – 05:07]Mr. Kennedy wrestled for WWE from 2005 to 2009. He won the 2007 Money in the Bank contract, which he had to drop later due to injury, and held the United States Championship once.How Mr. Kennedy impressed The Undertaker in WWEIn the same episode of Mic Check with Mr. Anderson, The Undertaker stated that some wrestlers became anxious when given the opportunity to work with him.According to The Phenom, Mr. Kennedy made it clear from the beginning of their rivalry that he was not afraid to step up to the next level:"If he was intimidated, he never showed it, and he brought it, and if I have somebody that's aggressive, everything else I can figure out, and Ken brought that to the table," The Undertaker said. "We just had really, really good chemistry." [From 5:08 – 5:24]The 60-year-old also addressed why former WWE Chairman Vince McMahon fined him after an unscripted WrestleMania moment.Please credit Mic Check with Mr. Anderson and give an H/T to Sportskeeda Wrestling for the transcription if you use quotes from this article.