Berserk Button: Don't mention to him that his wife left him because he pushed her away.
The Comically Serious: The movie's straight man, save for a quick scene in the first movie where he's telling J a joke and laughing a little too hysterically about it and while singing along to Elvis Presley in the tunnel.
Genius Bruiser: He can beat aliens in a foot race and punch some of them out. But he's also a lateral thinker able to see the forest when everybody else is focused on the trees, and is usually able to make logical leaps that K can't.
Obfuscating Stupidity: To a degree. The entire first act of the movie is designed to show that his streetwise smart-ass routine is largely a put-on and he's actually a very good, and even insightful, detective.
Older than They Look: Is treated as a fresh-out-of-college pup by K and the others despite his experience in NYPD. In the third movie he's revealed to be pushing 50!
Pre-Mortem One-Liner: To Serleena: "Your flight's been canceled!" Of course, she got better...temporarily.
Ripple-Effect-Proof Memory: Due to having been talking to K when he was Ret Goned, he apparently caused a temporal fracture that prevented his life story or memories from changing any as time reordered itself. Apparently, it induces a craving for chocalate milk.
Hero Killer: Killed J's father, killed K in a alternate reality.
I Hate Past Me: He doesn't even like himself in the past, seeing his past self the responsible of his failures. The feeling, obviously, is mutual for the '69 Boris who considers his older version the cause of his future fail.
Near Villain Victory: In the modified present he actually succeeds into killing K and spreading the Boglodite invasion on earth and probably consuming the entire planet. This is only prevented by J's interference in '69.
Sealed Evil in a Can: They built a prison specially for him in the moon (though it seems there are other prisioners there), his escape kicks off the plot (literally: it is the opening scene of the movie).
Ungrateful Bastard: He lets his girlfriend die, even after she sprung him out of prison...
Villainous Breakdown: Future!Boris becomes increasingly (more) wrathful when he starts to lose the edge of the battle, culminating in the scene where he falls off the plataform screaming "IMPOSSIBLE!".
Why Am I Ticking?: Her bracelet turns out to be a nuclear grade weapon that goes off if the light doesn't get off Earth.
Played By: Michael Stuhlbarg
"The bitterest truth is better than the sweetest lie."
Adorkable: The goofy hat and chipper personality just make his adorable.
Blessed with Suck: He has no ability to tell possible futures that won't happen from the ones that will, which is harrowing in situations where he has no idea whether he's about to die or not, and usually sees them months before they happen or are even relevant in the first place. He considers the constant visions "a pain in the ass."
Cloud Cuckoo Lander: A symptom of being The Omniscient. He literally sees things that aren't there and for the most part never will- so he comes off as outright kooky a lot of the time. Though... given his maniacally childish glee at the prospect of using a jetpack, that might not entirely be due to future shock.