This post contains spoilers for Season 7, Episode 6 of Game of Thrones.
Well. It finally happened. One of the dragons is dead. RIP Viserion.
The first time we see him is actually before he's born, when Daenerys is given the dragon eggs back in Season 1. That's Egg-Viserion just chilling in the middle, between Egg-Drogon and Egg-Rhaegal.
We finally see Viserion and his siblings as newly hatched baby dragons in the Season 1 finale. That's lil' Viserion climbing up Dany's leg.
Viserion doesn't get a lot of screentime in Season 2 (Drogon hogs the spotlight, classic Drogon). But all three dragons are seen in the finale, after they're kidnapped by the warlocks of Qarth (prompting Daenerys to spend a lot of time screaming, "Where are my dragons?!"). Dany finally finds them in the House of the Undying in Episode 10.
Look how cute lil' Viserion is!
Along with Drogon and Rhaegal, he totally roasts the warlock Pyatt Pree, allowing them all to escape the House of the Undying.
In Season 3, Viserion is there with Drogon and Rhaegal when Daenerys gains the Unsullied at Astapor.
When she later meets with a slave master of Yunkai, Viserion is perched menacingly above her head.
He manages to catch the piece of meat Daenerys throws and scares the hell out of the slave master.
All three dragons fly around in a display of power/freedom when the slaves of Yunkai escape the city and declare Daenerys "Mhysa".
The dragons are the best part of this scene, lbr.
In Season 4, we see Viserion flying around with Rhaegal while Drogon gets head scratches from Dany. Viserion and Rhageal then fight over a lamb, which Drogon promptly tries to take from them like the domineering big brother he is.
After Drogon kills a little girl, Dany locks Viserion and Rhaegal up. Even though they didn't do anything wrong!
Honestly I'm still mad about this. Look at Viserion trying to get free! Look at them both crying for their mother!
In Season 5, Daenerys visits Viserion and Rhaegal after Daario suggests she isn't much of a dragon queen without her dragons. She sees that her babies have grown a lot, despite being in captivity – and that they're both pretty pissed with being locked up.
They seem to forgive her somewhat when she brings them a snack (one of the noble leaders of Meereen).
Drogon has been flying free this whole time, and manages to rescue Daenerys from the Sons of the Harpy in the Season 5 finale, flying away with her. In Season 6, we learn that Viserion and Rhaegal, who are still chained up, have stopped eating since their mother left the city. Tyrion, who has arrived in Meereen by this time, talks about how dragons don't do well in captivity, and sets them free.
It's not until Daenerys returns with Drogon in the Season 6 finale that Viserion and Rhaegal blast themselves out of the catacombs they've been held in.
It's kind of heartbreaking to see how small Viserion and Rhaegal are compared to Drogon. While he was always the biggest of the three, the fact that the other two were kept in captivity stunted their growth.
But it's also completely cool to see the three dragons work together to properly fuck shit up for the first time.
Season 6 ends with Daenerys finally sailing towards Westeros with all three of her dragons flying overhead.
It's followed up nicely at the end of Season 7, Episode 1, when Daenerys arrives at Dragonstone and the dragons immediately make themselves at home.
We see a lot of them flying around this season, especially Viserion and Rhaegal. It's the two of them who Daenerys and Jon watch in Episode 3, when she tells him they were named after her brothers.
One of those brothers being Rhaegar, Jon's real father.
It's also the two of them that the gang are watching when Daenerys decides she should finally ~be a dragon~ and asks for Jon's advice.
We see Viserion and Rhaegal still happily flying around when Daenerys returns from battle with Drogon.
Fast-forward to this episode, and Viserion spends his last moments at Dragonstone napping with Rhaegal and Drogon.
North of the Wall, he bravely flies into battle and torches a bunch of ice zombies like a goddamn hero.
And then the Night King gets him and IT'S NOT OK.
Drogon's screams, Rhaegal's distress, Dany's heartbreak, Jon's anger, everyone's shock... ahhhh it's just too much.
And then the Night King REALLY got him and IT'S REALLY NOT OK.
THIS BABY! DESERVED BETTER!
In all seriousness, this is huge. People have been speculating for years about who would be the third dragon rider (assuming the other two are Daenerys on Drogon and Jon on Rhaegal, the dragon named after his father), and it looks like it's actually going to be the goddamn Night King. A battle between the fire and ice dragons seems set for the future, and it's going to be absolutely fucking heartbreaking.