Thieving Magpie (Revised) Cred. Torchbeareraxel

You learned how to conjure an otherworldly entity in the form of an animal to your side. You & your companion work in tandem to accomplice your goals.

Partner in Crime

Starting when you select this archetype at 3rd level, you can cast the find familiar spell as a ritual. When you cast find familiar you can choose from the following forms for your familiar to take: A cat, any corvid (use Raven statistics), ferret, monkey, rat, spider, squirrel, weasel, or any other creature the DM allows.
Your familiar gains Your proficiency bonus in everything.

Mugger

At 3rd level, whenever you deal sneak attack damage with a melee weapon attack that you were granted advantage on by your familiar performing the Help action, you steal a number of coins (or small obects with equal value) from the creature equal to the sneak attack damage dealt. The DM has final say on what you steal. You cannot use this feature unless you have a free hand.

 

Slippery as a Snake

At 9th level, Your familiar can use its bonus action to use the dash, disengage, or hide action.
Also whenever your familiar is attacked or forced to make a saving throw you can use your reaction to dismiss it as described in the find familiar spell. When dismissed in this manner it is no longer effected by whatever triggered the saving throw.
In addition whenever you use your uncanny dodge feature or succeed on a dexterity saving throw that evasion effects, you can move 5 feet without provoking attacks of opportunity.

Growing Together

Starting at 13th level, your familiar gains additional hit dice equal to your proficiency modifier and hit points as befits the hit die type. It gains a further hit die whenever your proficiency modifier increases.

 

Act As One

At 17th level, whenever your familiar uses the help action to assist you, you gain advantage as usual but you also add your proficiency modifier to all ability checks and weapon damage rolls you make until the start of your next turn so long as your familiar is within 5 feet of you.