Lag monster 

A supposedly mythical creature that causes lag. Said to have been only seen by veterans of the internets

Mommmmmmmmmy I had that nightmare again with the lag monster.. can I hug my modem...

Lag monster by Homoriffic December 13, 2006

Complete monster 

A villain that is the of the worst of the worst and sinks to the lowest of the lows..

Sosuke Aizen from Bleach is a complete monster, he does some truly vile things to Ichigo, his friends and even his own followers.

Complete monster by L2J July 20, 2012

M-m-m-monster Kill 

A phrase from Unreal Tournament and Unreal Tournament 2004 used as an award for getting 6 kills in a short amount of time. The effects in the sound are the letter M skipping 3 times (hence M-M-M-) and the word Kill echoing three times.

Awards preceding Monster Kill are Double Kill, Multi Kill, Mega Kill and ULTRA KILL, with LUDACRIS KILL! and H O L Y S H I T! coming after Monster Kill.

UT Announcer: Double ki- Multi kill! Mega KillULTRA KILL!!! M-M-M-MONSTER KILL!

(note: the reason multi kill and mega kill are shortened is that usually the player is getting kills so quickly that there is not enough time for the announcer to utter the entire phrase and it is cut off, replaced by the next award sound. The ULTRA KILL phrase is also commonly completely replaced by the announcement of Killing Spree, when the player scores 5 kills without dying.)

M-m-m-monster Kill by Reginald Maulding November 16, 2006

Mass Monster 

A Mass Monster is a person who is consisted of nothing but pure hard gained muscle. They usually skip most of their classes and go out of their way to go to a school gym. The weight room is pretty much their second home.

What’s that clanging noise in the weight room? I thought it was closed.
Oh that’s probably just Elijah being a Mass Monster .

Mass Monster by YazDef February 20, 2020

The one eyed monster 

Term/code name for your penis

I gotta go take the one eyed monster to the optometrist.

The one eyed monster by Tony GuizzettiKingTG December 13, 2017

hide the monster 

This is a slang term for the act of having sex.
inserting the penis in the vagina aka hiding the monster

hey what did you two do last nite.
oh we went down in the basement and played hide the monster.

hide the monster by [e-mail] January 24, 2008

sleeve monster

the magical creature that eats the sleeves off of men's t shirts in the morning as they leave their house, thus resulting in the tough guy sleeveless t shirt look

"oh shit....sleeve monster caught you this morning huh?"

sleeve monster by P Mills October 8, 2008