Sleeper OP 

A character in a video game that is simply too strong (overpowered, or OP for short), but not many poeple realize it (yet), hence the "sleeper" part.

This is likely due to the fact that when a new version of a game comes out, it takes a while for people (including some pros) to adjust to the new meta game and rather stick to the same staple set of popular overpowered characters (sometimes despite nerfs) out of comfort instead of trying to discover new ones.

This is NOT related to special snow flakes that somehow made a bad character work against all odds in 1 out of 100 games; Sleeper OP is legit broken, it's just known by the unenlightened masses.

When the Sleeper OP char becomes common knowledge, it loses that status.

Term originated in League of Legends.

Player A: LUL why you pick the Merchant, he's trash.
Player B: Nah man this is 0.24 Merchant, meta sheep just haven't caught on. Merchant Sleeper OP
*PLayer A gets obliterated by Merchant*
Player A: You just got lucky, Merchant sux!

Sleeper OP by Han shot in between November 1, 2018

Min Sleeper 

is a person that recieves minimum sleep because they spend all day playing runescape... Therefore they look like the grim reaper (Which rhymes).

Runescape-king007blad: Yo word up zezima
zezima:nuttin much man... just trippin
Runescape-king007blad: You look phyched dude. Go get some sleep.
zezima:ya trick ya. Get out my face. I aint no min sleeper!! ... Throw some D's on it.

Min Sleeper by Terry Houghton January 8, 2009

jeffy sleeper pick 

A fantasy football draft pick who can end up having just a shredded bit of success throughout the entire football season, or be the reigning NFL MVP. Is typically made by guys who always qualify for the consolation bracket each year.

Guy 1- "Aaron Rodgers was my jeffy sleeper pick this season."

Guy 2- "Dude, Aaron Rodgers was the top ranked QB in the draft rankings"

Guy 1- "Yeah well nobody else Tweeted that they were thinking about drafting him, or mentioned his name in the last ten minutes, so therefore he's my jeffy sleeper pick."

jeffy sleeper pick by kenny-wheatons-gonna-score October 27, 2010

Gorgeous Sleeper 

When someone looks really good when they sleep. They are filled with such beauty the person looking at them will have to leave the room because they are so overwhelmed with jealousy that that person looks much more good looking than someone who is awake.

JR is not a gorgeous sleeper, but Tracey, on the other hand, is the most gorgeous sleeper there has ever been.

Wow, look at Tracey she is a true gorgeous sleeper.

Gorgeous Sleeper by Saagwa November 24, 2011

fly sleeper 

a person who sleeps with a different people over and over like a fly to food

Tina: are you still going out with rob
April: he was a fly sleeper

fly sleeper by llama da man July 23, 2014

Caledonian Sleeper

At a Scottish wedding when a drunk Groomsman targets a passed out/sleeping guest at the reception (after party). The aforementioned lifts his kilt and proceeds to put his flacid penis in the unsuspecting sleeping victims mouth. Once fully inserted the Groomsman then motions as though he is activating the pullchord of a locomotive and yells "Choo Choo. All aboard!"

Cameron was looking forward to Donald and Morag's wedding. However he would not be drinking incase Hamish inflicted a Caledonain Sleeper on him if he passed out. Hamish was famous for his Caledonian Sleepers at weddings.

Caledonian Sleeper by CopeDawg February 17, 2018

Puddle sleeper 

Noun - Someone who sweats enough to make a puddle when they sleep

The fat kid was bullied cause his mom thought he peed the bed but in reality he was a puddle sleeper

Puddle sleeper by Puddlemaster3.14 December 30, 2018