The name of a fictional character played by Graham Chapman in the Monty Python film Life of Brian. Nowadays the name is used as a joke on Ifunny and Tumblr as a way to say Big D*ck without being flagged for an inappropriate comment on a post.
Side-Note: the guards in the Biggus Dickus scene were supposed to have a straight face the entire time but Graham Chapman decided to put a spin on the way he said the name and the director decided to use it in the final cut of the film.

Pontius Pilate : I will not have my fwiends widiculed by the common soldiewy. - - Anybody else feel like a little... giggle... when I mention my fwiend... Biggus...

another guard chuckles

Pontius Pilate : ... Dickus?

more chuckling

Pontius Pilate : What about you? Do you find it... wisible... when I say the name... 'Biggus'...

chuckle

Pontius Pilate : ... Dickus?

both guards chuckle

So all I gotta say to get top comment is Biggus Dickus?

Biggus Dickus by Thatguywithannoyinggirlfriend July 25, 2019

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Biggus dickus

Is a friend of Pontius Pilate Whom can’t seem to work out what is so funny about his name. He Is often ridiculed by the common soldiery also has a wife you know what her name is incontinentia buttocks.

“Does and body else feel like a little giggle when I mention my friends name....biggus dickus”

Biggus dickus by Biggusdickus September 12, 2019

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Dickus

Noun: Generic, ubiquitous term of derision, fairly innocuous, used mostly "friend on friend", has become completely mainstream

Hey, Dickus! Could you lend me $5.00?

Dickus by ky2 March 8, 2008

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Biggus Dickus

While a largely unknown person, Biggus Dickus is said to be a very great friend of Caesar. Anyone daring to laugh at his name is said to end up being a gladiator. His wife's name is Incontinentia Buttocks.

I heard this dude ended up as a gladiator because he laughed when he heard the name 'Biggus Dickus'.

Biggus Dickus by fixo January 7, 2019

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