|“||How many times do I need to kill you?||”|
Originally, Kol pretended to be Jeremy's friend while the latter was in Denver so he could keep an eye on him. Later their relationship turned antagonistic, especially when the revelation of a cure for vampirism came up. As Jeremy was capable of finding it with his Hunter's Mark, he was crucial in the search. However, getting the cure would mean awakening Silas, whom Kol was terrified of. He tried to cut off Jeremy's arm to avoid the results of the Hunter's Curse, but in the end, Jeremy managed to kill the vampire who used to be his 'friend.'
After the war with Klaus put Jeremy in harm's way, Elena had Damon compel her brother to go to Colorado, away from all the violence, which Jeremy did. However, Klaus wouldn't let such a noticeable target escape that easily and had Kol follow Jeremy to Colorado. Jeremy had never met Kol so was unaware of who he was, leading to a false friendship that was all a ploy by Kol to keep a close eye on Jeremy. He spied on Jeremy for Klaus while under the charade of being a friend, even willing to kill Jeremy if Klaus gave the go-ahead.
In Heart of Darkness, when Damon and Elena came to Denver in need of Jeremy's assistance, Kol intercepted them at the batting cage, revealing his true nature to Jeremy after attacking Damon with a baseball bat. He half-halfheartedly apologized but admitted that they were not "buds" before trying to beat Damon further. When Jeremy, Damon, and Elena escaped, Jeremy still couldn't believe that Kol had been a vampire the whole time to which Damon responded with an abrupt comment over how Jeremy couldn't have made a real friend as fast as he had become friends with Kol.
- Kol: (to Jeremy) "No hard feelings, mate, but we're not buds."
- Kol: "Jeremy, we were mates in Colorado. You're a smart lad. Why don't you call off this imbecilic treasure hunt?"
- Jeremy: "I'm not calling anything off... mate."
- Kol: "Well, I could kill you. But then I'd have to deal with the hunter's curse. And I, I don't particularly feel like being haunted for the next century. Better idea. I'll just rip off your arms."
- Jeremy: "How many times do I need to kill you?"
- Kol: "Jeremy Gilbert. Welcome back. Now, what's the saying? Kill me once, shame on you. Kill me twice, shame on..."
- (Stefan comes up behind Kol and breaks his neck, temporarily killing him.)
- Stefan: "Let's leave it at that, shall we?"
- In Catch Me If You Can, Kol implies that they were friends in Colorado, even though he was ready to kill him during Klaus's plan to unbind them and even told Jeremy they weren't weren't friends immediately after he revealed himself to be an Original. It is unknown if Kol partially did genuinely enjoy acting like a friend to Jeremy, though it is hinted at, as he reminded Jeremy they were friends while giving him the chance to stop trying to grow his mark, only trying to hurt him again when he refused.
- Steven R. McQueen and Nathaniel Buzolic who portray them are best friends in real life.
- It is currently unknown if Jeremy knew about Kol being resurrected.
- They were brought back to life by a witch who loved them.