Michael C. Hall previously played a funeral home director on Six Feet Under. So when Dexter goes to a funeral home in the season 5 premiere, and the roles are reversed, the show makes the most of it, from a set that looks like the Fisher funeral home to the director offering tissues.
Enver Gjokaj guest stars as a character named Viktor, possibly a reference to his role as Victor in Dollhouse.
Cody was played by Daniel Goldman in Season 1, and by Preston Bailey from Season 2 onward.
Taken Up to Eleven with Harrison: he was portrayed by Brandon Michael Bass in Season 3 (during an Imagine Spot), by several uncredited babies in Season 4, by twins Luke and Evan Kruntchev from Seasons 5 to 7, and by Jadon Wells in Season 8.
Stunt Casting: From Season 3 onward, moderately big names are brought in to play major recurring characters.
Jimmy Smits in Season 3.
John Lithgow in Season 4.
Julia Stiles, Jonny Lee Miller, and Peter Weller in Season 5.
Colin Hanks, Mos Def, and Edward James Olmos in Season 6.
Ray Stevenson and Yvonne Strahovski in Season 7.
Charlotte Rampling and Yvonne Strahovski (again) in Season 8.
Trolling Creator: The show seems to go out of its way to make things as uncomfortable as possible for Michael C. Hall and Jennifer Carpenter by ramping up the levels of Cast Incestafter their real-life divorce. Probably the only case of the creator trolling the cast instead of the audience.
What Could Have Been: After the series finale aired, an interview with former showrunner Clyde Phillips (who stepped down after Season 4) revealed how he would have ended it:
"In the very last scene of the series, Dexter wakes up. And everybody is going to think, 'Oh, it was a dream.' And then the camera pulls back and back and back and then we realize, 'No, it's not a dream.' Dexter's opening his eyes and he's on the execution table at the Florida Penitentiary. They're just starting to administer the drugs and he looks out through the window to the observation gallery. And in the gallery are all the people that Dexter killed—including the Trinity Killer and the Ice Truck Killer (his brother Rudy), LaGuerta who he was responsible [for] killing, Doakes who he's arguably responsible for, Rita who he's arguably responsible for, Lila. All the big deaths, and also whoever the weekly episodic kills were. They are all there. That's what I envisioned for the ending of Dexter. That everything we've seen over the past eight seasons has happened in the several seconds from the time they start Dexter's execution to the time they finish the execution and he dies. Literally, his life flashed before his eyes as he was about to die. I think it would have been a great, epic, very satisfying conclusion."