Disclaimer: I do not own Merlin or any of the characters.
50 Ways to Annoy Gaius
Make kissy kissy noises whenever you see him talking to Uther.
Tell him to stop perving on Morgana.
For added effect after 2), whenever he is with Morgana tell him to stop looking down her top.
Tell him that he didn't need to worry when Merlin was feverish and shouted out "Faster, Arthur, go faster!" – because Merlin shouts that out in his sleep every night anyway.
Creep up behind him and shout "I DON'T BELIEVE IT!"
Tell him you hope he hasn't banned Merlin from keeping pets because Merlin's keeping a dragon in the castle.
Tell him Merlin's been sneaking out of his room at night to go see Arthur.
Tell him Merlin's been getting himself thrown in the dungeons/stocks on purpose because he has a bondage fetish.
Ask him if he's getting a badge for Merlin to wear that says "Gaius's dogsbody".
Say to him – "You know what Gaius? Why don't you go fetch the fresh rosemary for a change, instead of getting everyone else to do your dirty work for you!"
Tell him you know that Edwin was really a past lover of his.
Ask him if he fancies eating some beetle. Tell him it tastes just like chicken.
Tell him you know he only went in Merlin's place to see Nimueh because he likes her.
Repeat over and over whenever Gaius is in the presence of Morgana or Gwen – "You should be ashamed of yourself! You're old enough to be her grandfather!"
Place a whoopee cushion on Uther's throne seat and say Gaius did it.
Ask him why he wears that "brown dress thing".
Say to him "Don't you ever get tired of being right?" Repeat.
For added effect after 17), add the last time – "Oh wait, you were wrong about Morgana! Edwin found blood in her ear that you missed!"
Tell him that Merlin is jealous that he got to put Arthur to bed when he knocked him out with that sleeping potion.
Buy him a t shirt that says "Big G disapproves of this shiz".
Tell him you know he's tried Uther's crown on once or twice in secret to see what it feels like.
Nag him constantly to tell you all the King's secrets.
Tell him that his moment in the rain with Merlin was cheesy and has been done before.
Comment on his promotional wallpaper that the dragon seems to be trying to eat his head.
Ask him if he's jealous that Morgana and Uther are close.
Tell him you thought it was hilarious when he said the wrong words when trying to use magic against Edwin
For added effect after 26), imitate Gaius saying the wrong words to a group of others when Gaius is within earshot.
Tell Gaius he's obviously past it as a court physician or Uther wouldn't have appointed Edwin so easily.
Ask him if he's taught Merlin Defence Against the Dark Arts yet.
Tell him that the dragon wants him to bring it some magazines because it's kinda bored all chained up.
Ask him if he goes to bingo.
Ask him if he has a walking stick/false teeth.
Graffiti all over the castle walls "Gaius is so pious, I wish he would go and die-us".
Tell Gaius that Merlin wears the neckerchiefs to cover up hickeys Arthur has given him.
Write "Uther was here" on the inside of Gaius's underwear.
Wait until Lancelot, Merlin and Arthur are together in the royal court, then ask Gaius if he's noticed any homoerotic tension recently.
Tell him you think he's a dirty old man then refuse to elaborate.
When you are with Gaius and Uther, ask them if they've ever been to Hawaii. Tell them it's really nice, and show them the Hawaiian dance, accompanied by – "A-Nimueh, A-Nimueh, A-Nimueh, A-Nimueh," as you sway.
Mix up all the labels for his bottles.
Replace all his herbs and medicines with bottles of pink glitter.
Take him aside, and tell him in a low voice, you know he's getting older now. Offer him some laxatives to "help move things along".
Ask him if he practised lecturing Merlin or if he's just naturally good at it.
Ask Gaius if he liked Uther in Buffy the Vampire Slayer and if he digs the librarian look.
Tell him he's a dumbass for not knowing that a mythical creature with the wings of an eagle and the body of a lion is a griffin.
Nag him to give you his hangover cure mixture.
Call him "physician" like Uther does.
Ask him if he uses ear wax to make his candles.
Tell Gaius that his one redeeming feature is making important observations such as "Lancelot needed you and you needed Lancelot. Your destinies were entwined."
Ask him if he's ever considered anti-wrinkle cream.
Tell him that wearing the brown sack dress makes him look like a walking turd.