The Rascal

Rascals are a special kind of rogue. Where other rogues learn to fight, sneak, or steal alone, a rascal tirelessly trains up animals to do these things for and with them. A rascal's animal companions are the secret to their success and the key to their accomplishments. Others may go it alone, but a rascal knows there is safety, and success, in having their companions watching their back.

Rascal's Companion

At 3rd level, you gain a beast companion that accompanies you on your adventures and is trained to assist you. Choose a beast that is no larger than Medium and that has a challenge rating of 1/2 or lower. Add your proficiency bonus to the beast’s AC, attack rolls, and damage rolls, as well as to any saving throws and skills it is proficient in. Its hit point maximum equals the hit point number in its stat block or four times your rogue level, whichever is higher. Like any creature, it can spend Hit Dice during a short rest to regain hit points. Your companion also gains your Stealth modifier, and will enter stealth whenever you do.

The beast obeys your commands as best as it can. It takes its turn on your initiative. On your turn, you can verbally command the beast where to move (no action required by you). You can use your bonus action to verbally command it to take the Attack, Dash, Disengage, or Help action. If you don't issue a command, the beast takes the Dodge action.

If you are incapacitated or absent, the beast acts on its own, focusing on protecting you and itself. The beast never requires your command to use its reaction, such as when making an opportunity attack.

If the beast dies, you can obtain a new companion by spending eight hours bonding with a beast that isn’t hostile to you and that meets the requirements.

Companions Edge

At 3rd level, you have trained your companion animal to assist you with certain tasks. As long as the beast is with you, you have expertise in an additional skill of your choice when you gain this feature, as well as proficiency in Animal Handling if you don't already possess it. 

Deeper Bond

At 9th level, your bond with your animal companion has deepened considerably. You may issue commands to your companion without speaking, using only a series of subtle gestures and changes in facial expression. In addition, you can understand its attempts to communicate with you, if the message or idea it is trying to convey can be reduced to a three-word phrase (i.e., 'Door is locked', or 'I swallow gem').

Your companion has also learned a thing or two from you. The beast now gains proficiency in the skill you chose with Companion's Edge, and adds your proficiency bonus to those checks. Additionally, your companion "levels up", gaining your proficiency bonus to its Ability Scores. It is now able to wear armor & weapons custom designed for it as well, increasing its AC and Damage by +2.

Exceptional Trainer

Beginning at 13th level, the beast's attacks now count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

In addition, you may now bond with and train an additional animal companion of Medium size or lower and that has a challenge rating of 1 or lower. This creature can be a Beast, Elemental, Fey, or Monstrosity, but it still must not be hostile towards you. 

You also gain Advantage on Initiative rolls as long as one of your companions is with you.

Double Team

At 17th level, attacks made in conjunction with your animal companion become especially lethal. When the beast assists in creating the conditions for a Sneak Attack, such as by using the Help action or by being within 5 feet of a target, your Sneak Attack damage against that creature increases by 3d6. If both animal companions assist, then increase the damage by an additional 3d6 for a total of 6d6.