VIDEO: Watch RTÉ staff get pranked with a giant megaphone

(But don't mess with Rick O'Shea)

You know the office prankster - that loveable scamp you want to kill, but at the same time, acknowledge he's great craic?

Enter Carl Mullan, creeping up behind unsuspecting presenters and office staff to scare the living daylights out of them. Screams aplenty.

Except for Rick O'Shea. You do NOT mess with Rick O'Shea. He will kill you.

Scary chap, is Rick. Don't let his habit of giving out Curlywurlys at public events fool you.

Watch the whole clip below:

Carl is the same prankster who terrorised the staff once he got his hands on a selfie stick - inserting himself into their workday - whether they liked it or not.

And naturally, it's O'Shea at the end you have to watch out for. Again.