“None the less it is a drug and too much can kill you.”
Magic Mushrooms, or simply 'shrooms, are a common hallucinogenic drug. It is known to have no negative side effects at all, in fact being beneficial in some cases, causing a power-up, or giving you the inspiration to write a book for the Bible.
Shrooms are a very strange drug. Shortly after eating them you will start seeing things that aren't real. Everything will become very cartoonish and gay looking. You will start imaging that you are a short fat plumber, and you will walk around screaming " It's a me, Mario." You will also think that for some reason you have to rescue a princess that got captured by a giant horny turtle. You may also start eating things off of the ground for no logical reason, like flowers and leafs and and stuff that you will think will give some sort of magical power. You may also start stomping on people's head and calling them Goombas. You will also start thinking you have a dumb-ass brother named Luigi who is inferrior to you in every way. Oh and you might also think that for some reason you are riding on a little green dinosaur thingy that you call Yoshi. But when you wake up you will find out that none of that was real]
Being on shrooms sounds like this 
If you weigh 60kg, About 1.5kg dried Psilocybe cubensis will probably kill you, as they absorb water, swell and cause your stomach to explode, covering your friends in blood and intestines.(See video below...) Anyone nearby risks injury from bone fragments etc. If you have a very very very large stomach, eating 15kg will cause your mind to implode and possibly destroy the universe.
While high you may experience terrors, these can be terrifying and dangerous, here is a typical scene in which three characters experience terrors for the first time
Person 1: FUCKING UGLY SHITTY FACE! EAT MY BIG ELEPHANT DICKS BITCH!!!... DID YOU HEAR THAT... ITS THE FUCKING POLICE!!!!!!!!!!!!!!!
Jon Stewart: SHIT DUDE... THROW ALL OUR SHIT OUT THE WINDOW
Person 1: WHO THE FUCK ARE YOU
Jon Stewart: I'M a Phasm I RAPE YOUR genitalia FOR A LIVING
Person 1: ARE YOU IN MY HEAD
Jon Stewart: YES...
Person 1: SCUMBUCKET GET a Phasm OUTTA MY HEAD
*bangs head on wall*
Person 2: AUTOFELLATIO WHAT THE FUCK ARE YOU DOING ??!!
Person 1: GOTTA GET a Phasm OUTTA MY HEAD
Person 2: VAGINA Jon Stewart a Phasm! WHERE IS IT
Person 1: IN MY HEAD!!!!!!!!!!
Person 2: BITCH LET ME GET IT OUT
*picks up pick axe*
Person 1: SHIT DUDE
Ring ring ring ring ring ring ring, banana phone, Ding dong ding dong ding dong ding, donana phone
Person 3: HOLY FUCK! BANANA PHONE DON'T TOUCH ME
Person 2: BUT HOW ARE WE GONNA GET a Phasm OUTTA YOUR HEAD?
Person 1: GIMME THE PICK AXE I'LL DO IT MYSELF
Person 2: DON'T FUCKING TOUCH ME I'LL GET BANANA PHONES
Person 3: Hey guys, I'm an orange, I've peeled myself, who wants to eat me?
Person 2: Fuck a Phasm lets eat him
Person 1: What about the police?
Person 2: GREAT GOOGLY MOOGLY THE POLICE!
Person 1: THROW YOURSELVES OUT THE WINDOW
Person 3: No way, not until you eat me
Person 2: Okay, lets eat him, then crack your head open, then jump out the window.
Person 1: He tastes good...
Person 2: FAG HE'S DEAD!
Person 1: IRATEGAMER LOVIN' SHITHEAD WE'RE CANNIBALS!
Jon Stewart: I'm not...
Person 1: FUCK OFF RANDOM VOICE
Person 2: WHY THE BATHING SUIT AREA ARE YOU TELLING ME TO FUCK OFF?
Person 1: CHIGGER I WAS TALKING TO a Phasm
Person 2: DICKFACE ARE YOU CALLING ME a Phasm
*embeds fork in person 1's head*
Person 2: FUCK OFF PISS CUNT JESUS FETUS JAP THE POLICE!!!!!!!!!!!!!!
*Jumps out of window*
Person 2 survived the fall, but thought that he was being uninvitingly insulted by a holster employed by Jon Stewart as a waiter. He promptly insulted a fork into his cheek killing him instantly. The police never found his body... But all that is irrelevant, because that little conversation was so poorly written and impossible to follow that I'm sure everyone just skipped to the aftermath like me.
edit THATS WHY DRUGS ARE BAD
I lied, they are very good, but don't be so uninviting like the n00bs in that story
fact: taking shroom will inevitably cause your genitals to grow to an enormous size and give you the urge to take it in the ass from a panda bear
Shrooms can be very fun if used with the right person for example, If a conservative christian were to eat mushrooms he most likely would see Jesus and start to think it was the rapture in which case he will go to hell as anyone with those types of ethics belongs in hell. However if you are more of a mindset of acceptance of other people then as a giant rainbow fish floats out of your friends mouth as he babbles about something stupid instead of being freaked you most likely will be happy you don't need to here your stupid friend talk about stupid shit and will be much more pleased watching the fish swim around the room until it breaks your T.V.