While AMC's apocalyptic juggernaut The Walking Dead seems like a show likely to run for multiple more seasons, it still has a good ways to go before it manages to catch up to The CW's Supernatural, one of the current elder statesman of TV drama. Supernatural holds the rare distinction of actually being older than the network that airs it, having debuted on The WB in fall 2005, less than a year before that network would merge with UPN to become the current CW.

Now in season 12 -- with season 13 already ordered by The CW -- Supernatural seems to have no end in sight, at least as long as stars Jared Padalecki and Jensen Ackles remain up for more monster-hunting adventures as heroic lead duo Sam and Dean Winchester. While Supernatural has become well-known over the years for a tendency to bring back previously deceased characters for another hurrah, one important Supernatural character that hasn't been seen since the early years is Winchester dad John, at least in his grizzled adult form.

The lack of John is presumably due to the fact that actor Jeffrey Dean Morgan is basically always working, whether in films or on TV. Morgan's latest TV character is arguably his most iconic, that of The Walking Dead's murderous despot Negan, leader of the barbaric Saviors. However, while Morgan hasn't appeared on Supernatural in many years, he's far from forgotten, as evidenced by a none too subtle Negan shout-out present on the most recent episode. In the opening moments of 'Somewhere Between Heaven and Hell', Dean struts into frame covered in blood, with what appears to be Lucille swung over his shoulder. Dean then quips to Sam that their dad would've loved the weapon.

Naturally, this reference did not go unnoticed on social media for very long, with fans of both series quickly going crazy for the apparent crossover:

I CAN'T BELIEVE THEY HAD LUCILLE IN AN EPISODE.#Supernatural @JDMorgan Are you missing something? pic.twitter.com/Ufmnt1UmKH— T-MAC (@TONiANN_ROSE) March 10, 2017

This isn't the first time a crossover between the two shows has been teased, with actors Ackles and Morgan engaging in a playful exchange about Lucille on Twitter back in October. With this latest episode now aired, that at least explains why Ackles was standing around the Supernatural set with a replica of Lucille, outside of just wanting to have a laugh with his former TV dad.

One does wonder whether Morgan will ever actually return to Supernatural and play John one last time. Producers have made clear on many occasions that they would love to have him back, and that the ball is basically in his court on the matter. Thankfully, it's very likely that Supernatural will still be on the air at the point Morgan's tenure as Negan comes to an end.

Next: Walking Dead Season 7 Final Episode Synopses Tease ‘Heartbreaking Decisions’

Supernatural season 12 airs Thursdays on The CW.

Source: T-Mac