Nightwalker

Nightwalkers are an ancient circle of druids who are most in tune with the lunar cycles and nocturnal creatures. They are the unblinking eyes keeping watch over resting allies, as well as the swiftly approaching steps out of sight in the dark; while the circle is most known for their stealth and vigilance, they also have more secretive goals: watching over the border between worlds, specifically that of the Shadowfell, and keeping the natural world from being overrun.

Though they have a somewhat dark and sinister reputation among the uninformed, the nightwalker emphasis on stealth comes from a core belief of preserving silence and harmony with nature. Under the forms of various beasts and even plants they keep watch, hidden from sight and silent, walking among the darkness ready to leap into action.

Cat's Eye

Starting at 3rd level, your affinity for the nighttime wilds allows you to stay up deep into the night. You only require four hours of rest to gain the benefits of a long rest.

Fox Walk

When you choose this circle at 2nd level, you've gained wisdom from the athleticism of the fox, allowing you to maximize your agility and stealth. You can gain a Wisdom modifier bonus to an Athletics, Acrobatics, or Stealth check. You can do this proficiency bonus times a long rest.

Stealth Shifting

The rites of your circle grant you the ability to shift into more powerful and varied primal forms. Starting at 2nd level, you can use your Wild Shape to transform into a beast or plant with a challenge rating as high as 1. You can ignore the Max CR column of the Beast Shapes table, but you must abide by the other limitations there. Additionally, while in your Wild Shape form, when you're in terrain the form is native to,  you can move stealthily at full speed and have advantage on Stealth, Nature and Survival checks. You also gain Darkvision to 60 feet.

Starting at 6th level, you can transform into a beast with a challenge rating as high as your proficiency bonus minus one.

Freedom of the Wilds

Starting at 6th level, the primal magic suffusing you lets you avoid and subtly twist natural hazards to stride a smooth path. Moving through nonmagical difficult terrain costs you no extra movement. You can also pass through nonmagical plants without being slowed by them and without taking damage from them if they have thorns, spines, or a similar hazard.

In addition, you have advantage on saving throws against plants that are magically created or manipulated to impede movement, such those created by the entangle spell.

Ambush

When you reach 10th level, your mastery of stillness and explosive beastial power allows to blindside foes that haven't been able to make a start. If you hit a creature with an attack roll, the creature takes an extra 2d6 damage if it hasn’t taken a turn yet in the current combat. In addition, any hit you score against a creature that is surprised is a critical hit.

One With the Wilds

When you reach 14th level, your mastery of stealth has become so total you are, for all intents and purposes, invisible while maintaining a steady connection with the natural world. The first time you use your Wild Shape after a long rest, you are considered to be invisible. If a creature's passive Perception does not exceed your spell save DC, it does not automatically notice you; if it does, it must make a Wisdom save at the end of its turn if it is within 30 feet of you, noticing you on a success. This invisibility otherwise lasts as long as you are Wild Shaped, or until you make an attack, cast a spell that targets another creature, or choose to end it as a free action.