A dark haired elf stalks through the forest, bow in hand. Behind him is a huge brown bear, quietly pushing up behind. The elf turns at the sound, then smiles. He reaches into his pocket and pulls a strip of fish and feeds it to the bear. The elf scratches the bear behind her ears then continues on. His teeth start to grow and claws extend from his hands. His smile turns crooked, jagged teeth sprouting out. The two bears launch themselves on the passing nobles. 

 Beast Master revised is a subclass designed to give more than what the normal beast master does. After some thinking, I've decided to put together a Ranger/Druid hybrid, one that makes sense to me. One that allows the partnership of a beast and master but keeping the naturalism and spirituality of Druid, combining the two classes. 

Beast Companion

You spend 6 hours in your favorite terrain and find a beast of up to CR 1/4 your level (rounded down). The GM can make you roll a animal handling check (DC decided by GM) to determine how successful you are. Once you have found a beast, you must make a animal handling check (DC 12) each day for the next week or lose this companion. You may add one beast from your favored terrain to you creatures/companions list.

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 ranger level, whichever is higher. Like any creature, it can spend Hit Dice during a short rest to regain hit points.

During combat, your beast takes it's turn on your turn, but does not need your action or command to do so. However using a reaction for the beast does consume your reaction.

While traveling through your favored terrain with only the beast, you can move stealthily at a normal pace.

*You may only have one beast companion and one time, having more than one will result in losing the original*

Natural Link

Your beast grows stronger as you gain levels. *Note this does not have to be Ranger levels* At 3rd, 7th, 11th, 15th and 20th level your beast gains an additional +1 to attack and damage rolls made with it's weapon attacks.

This bonus will have to be added manually as I do not know how to add that :)

Expanded Spell list

You gain the knowledge of a practicing Druid therefore allowing you to take spells from the Druid spell list

Animal Tongues

At 7th level you have grown so comfortable a familiar with your beast, you are able to communicate to your beast as if you speak the same language. Other beasts of the same species as your beast can understand you also, however may not be friendly towards you because of this.

If a new beast is acquired, you must spend at least 3 weeks with this beast to gain this benefit.

Beast Shapes

At 11th level, you can use an action to transform into your beast for a number of hours equal to half your Ranger level (Rounded down).

When you transform to gain the Str, Dex and Con of your beast, but your Int, Wis and Cha stay the same. You cannot talk in your beast shapes and any equipment you are wearing when you transform is either absorbed or dropped (your choice). However, unlike the Druid wild shape, when you drop to 0 Hit points in your beast form, you do not revert back to your previous HP, you must make death saves as per being dropped to 0. Hence you are treated as if your non beast shape character has dropped to 0.

You gain all abilities of your beast while transformed (except multiattack). 

Beast Intensify

At 15th level, your knowledge of natural magic has allowed you to slightly shift the fey lines in your favor. 

As an action you can transform your beast into a size category larger, adding an additional damage die to each of its attacks. This power is limited however as afterwards your beast gains a level of exhaustion and must take a short rest to rid this. This effect can last up to 10 minutes. If the beast drops to 0 HP during this change, it reverts back to its normal size as if it dropped concentration.