The Nature Spirit

You make a deal with a nature spirit, granting you druidic like powers. These Spirits can be Nymphs, Ancient Druids, Dryads, and other creatures of the sort. They grant their warlock immense powers to help them in protecting and respecting nature. To be a Warlock of The Nature Spirit, is to take up the mantel of a Druid like role. To impose the power of nature on to others, to show it demands respect and should be treated with it as such. 

Expanded Spell List

The Nature Spirit grants you the entire Druid spell list to choose spells from. 

Nature's Friend

Starting at 1st level, You are able to communicate with any creature considered a Beast.

Nature's Worker

Starting at 6th level, you can call on your patron to alter the field of battle. Once per short rest as a reaction you can: Make difficult terrain in a 15ft square area to hostiles, or summon a swarm of tiny beasts to help in an allies actions (they take the help action, can't be targeted with a spell or attack, nor can they attack). Each effect lasts 1d4 rounds.

The time the effects last increase at 12th level to 2d4 rounds, and 18th level to 3d4 rounds.

Nature's Opening

Starting at 10th level, you use your powers of nature create an opening for you and your friends. Once per short rest as an action you can make one creature that you can see vulnerable to one damage type for 1 minute. If the creature is Immune to that damage type it is treated as resisted damage, if they are resistant to the damage type it is counted as normal damage.

Nature's Cocoon.

Starting at 14th level, you have greatly served your Nature Spirit Patron you gain the following:

You learn the language Druidic.

As a bonus action you can touch a creature the creature then must make a wisdom saving throw equal to 8 + prof. bonus + Charisma Modifier. On a failure they are wrapped in vines and are restrained for 3d6 rounds, while wrapped in the vines they can't take action or move, but they can't take damage nor age while trapped in the vines, if they are attacked then the attacker takes 1d12 psychic damage. Once they leave and they are attacked for 2d4 rounds they take 1d12 psychic damage extra on each attack that hit. On a successful Save the target takes 1d6 extra psychic damage on every attack that hits for 2d4 rounds.

You can use this ability once per long rest.