Unskilled Fighter

You are a common man who somehow ended up in a scenario where you need to know how to fight. 
Well guess what buddy, it ain't gonna be easy.

Competent worker

Choose a profession, you know, the one you abandoned to run about with a bunch of randomers

Barman

You gain advantage on investigation checks to identify Alcoholic drinks.

Beautician

You gain advantage on Perception checks to identify if people are in disguise.

Farmhand

You gain advantage on investigation checks to identify common crops.

Fisherman

You gain advantage on investigation checks to identify Fish.

Nursing Assistant

You gain advantage on Medicine checks to identifying the treatment of wounds but can't treat them yourself.

Shopkeep

You gain advantage on investigation checks to identify value of items.

Unemployed

You gain the benefit of a long rest on a short rest as you are used to falling asleep quickly and doing nothing.

Incapable leader

Disadvantage on any persuasion rolls to convince other player characters to follow your lead.

Delhi Belly

You are proficient at cooking but will suffer from food poisoning if you eat anything other than normal rations. (poisoned status)

Cowardice

Starting 3rd level

You are not suited to a life of violence. You can play dead on your first turn in the fight, you gain advantage on a stealth roll but must remain still for the duration of this ability and forgo your turns.
You can end this ability on any of your next turns.

Generalised anxiety disorder

Starting 3rd level

Advantage on perception checks due to increased anxiety which developed from being in danger all the time, however you take disadvantage against saving throws against being frightened.

Mania

Starting 7th level

You become so scared that you can enter a state of mania as a bonus action, you gain advantage on Dexterity saving throws and gain resistance to bludgeoning, slashing and piercing damage for 1 minute. When the mania ends you suffer 1 level of exhaustion and fall into a state of depression. Once per long rest

Self De-Faeces

Starting 10th level
When fighting a non-evil character you can use a reaction when you are about to be attacked to shit and piss your pants out of fear, you raise both your arms up over your head and begin to cry fearing for your life. The enemy must make a DC 15 Wisdom saving throw or have to pitty you so much that they chose another target. If there is no other target in range the enemy simply looks at you and almost sheds a tear as he sees how weak, sad and pathetic humans actually are. If they pass the check you still get bopped. 

If you take this action you take disadvantage to ALL ability checks for the next hour as you stink of piss and shit and cant concentrate. 

Fear the man that has nothing to lose

Starting 15th level
After watching you piss and shit yourself and generally be completely weird and insane for the entire time they've known you, your party start to realise you have nothing to lose, and nothing is more intimidating than a man with nothing to lose. You now gain expertise on intimidation checks against anyone whilst your party is present and can account for your insanity. But you have disadvantage against your actual party as they know how pathetic you are.

Awakening

Starting 18th level
You feel as if your efforts have been noticed by some unknown deity, you feel blessed by a presence. you feel yourself become more focused and observant, you can now perform a critical strike on a roll of 18-20. You feel stronger and more healthy like you could stay awake for days on end. Your skin starts to turn crimson, after a tenday your skin has become blood red, your eyes will glow blue, and you will realise you are special, you are the chosen one, Gruumsh the orc god who desires bloodshed and primal energy has seen your skills and is impressed you managed to survive as long as you have, you are now a vessel for bloodshed.