Chekov is a character from Star Trek: The Original Series. He appeared in 36 television episodes and in the six TOS films; he was portrayed by Walter Koenig.
He is also a character in JJ Abhram's reboot films (Star Trek, Star Trek Into Darkness and Star Trek Beyond); he was portrayed by Anton Yelchin.
They were looking to add in a new character to take the place of George Takei (Sulu) while he was off filming The Green Berets. They wanted someone who was youthful to capitalise on the Beatles/Monkees craze of the 60s, and he apparently looks sort of like Davy Jones.
Chekov was conceptualised as an Englishman at first, but was changed to be a Russian. There was a rumour that Roddenberry changed it because there was an article in Pravda which had a go at the show for not having a Russian member of the crew, but no American shows were airing in the USSR at the time, and no such article actually exists.
Amok Time
Who Mourns for Adonais?
Mirror, Mirror
The Apple
Catspaw
I, Mudd
Journey to Babel
Friday's Child
The Deadly Years
Obsession
The Trouble With Tribbles
The Gamesters of Triskelion
A Piece of the Action
The Immunity Syndrome
Private Little War
Patterns of Force
By Any Other Name
The Ultimate Computer
Bread and Circuses
Assignment: Earth
Spock's Brain
The Enterprise Incident
The Paradise Syndrome
And The Children Shall Lead
Is There In Truth No Beauty?
Spectre of the Gun
Day of the Dove
For the World is Hollow and I Have Touched the Sky
The Tholian Web
Elaan of Troyius
Let That Be Your Last Battlefield
The Mark of Gideon
The Lights of Zetar
The Way to Eden
The Savage Curtain
Turnabout Intruder
To utilise Tumblr venacular, he's my favourite little goober!
He is, quite frankly, silly and incredibly charming! If you plonked me onto The Enterprise right now I'd probably try and be friends with him, though I don't think I could knock the likes of Sulu off the best friend pedistal.
I love his quirk of just attributing everything ever to being a Russian invention or thing. He says Eden is right outside of Moscow, and who am I to go against his word?
I get that it was because the show was airing right in the middle of the Cold War and it was probably easier to just make him very very loyal to the USSR, but MAN does it have some very interesting implications about the USSR's future in Star Trek's universe.
You know what I both love and despise about his character? That fucking WIG.
Now I know that the wig was only temporary and at the start they didn't want to fuck up Walter Koenig's actual hair by giving him the Davy Jones cut, but couldn't they have picked a better wig? Like, that shit was atrocious to look at and very distracting; every time I see it I start giggling.
I like to imagine that the wig was almost symbolic of his first attempt at trying to experiment with his hair and that's why it looks so bad. Plus, I think it's very funny to image someone else on The Enterprise having to step in and start cutting his hair for him because they couldn't STAND to keep seeing that godawful haircut every time they were on shift or in the mess hall.
Every time I see him I want to eat glass and that's the single greatest compliment I could give!