Blooming Guardian

Petal Form. The blooming guardian can dissipate momentarily into a swirling cloud of petals and pollen to pass over brambles and slip through cracks. While in woodlands, the blooming guardian ignores difficult terrain and can pass through obstacles so long as there is a small passageway.

Budding Siphon. The Blooming Guardian is in a constant state of decomposition. To keep this entropy at bay, the flowers that cover its antlers continually siphon life from the surrounding area. All living creatures that enter or start their turn in a 20 foot radius of the Blooming Guardian must succeed on a DC 18 Constitution saving throw or take 15 (6d4) necrotic damage.
At the start of its turn, if the Blooming Guardian has dealt damage with its Budding Siphon trait, it gain 10 temporary Hit Points, plus 2 temporary Hit Points for each creature damaged beyond the first since the blooming guardian's last turn, to a maximum of 20 temporary Hit Points.

Animal Vision. The Blooming Guardian can tap into another animal's senses, allowing it to sense what the target senses for 1 hour. If the animal is unwilling, it must succeed on a DC 18 Wisdom saving throw, ending the effect on itself on a success. While tapping into the target's senses, the Blooming Guardian cannot use its own body's senses, but can change back and forth from its own senses to the targets as an action.

Innate Spellcasting. The Blooming Guardian can cast Speak with Plants and Speak with Animals at will.

Multiattack. The Blooming Guardian makes one Antler attack and one Hooves attack.

Antlers. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 31 (4d12+5) piercing damage.

Hooves. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 27 (4d10+5) bludgeoning damage. A creature hit by this attack must beat the Blooming Guardian in a contested Grapple check or be knocked Prone.

Goring Charge (Recharge 5–6). The Blooming Guardian uses its movement and can immediately use its Antlers action. Then, it Dashes and uses its Antlers action again. On a hit, the blooming guardian deals an additional 13 (2d12) bludgeoning damage, and the target takes a –2 penalty to its next Constitution save against Budding Siphon.

Wail of the Forest. If the Blooming Guardian is in Full Bloom and has not used its bonus action this turn, it confronts its mortality, causing its flowers to burst and spray their pollen, dealing 55 (10d10) necrotic damage. The Blooming Guardian then exits Full Bloom and can't enter it again for 2 rounds.All creatures in a 40-foot cone must make a DC 18 Constitution save.
A creature who succeeds its save by 5 or more takes no damage.
A creature who succeeds its save by less than 5 takes half damage.
A creature who fails its save by less than 5 takes full damage. Additionally, it has disadvantage on its next Constitution saving throw, and has its hit point maximum reduced by an amount equal to its hit dice maximum (for example, a creature with 12 hit dice loses 12 points from its hit point maximum). If this reduces a creature's hit point maximum to 0, the creature dies.
A creature who fails its save by 5 or more takes double damage, and suffers all other effects of a failure.

Full Bloom. The flowers on the blooming guardian's antlers bloom, unveiling their brilliance as they eat away at their host. While in Full Bloom, the blooming guardian's melee attacks deal an additional 5 (2d4) poison damage; on a hit, a target must succeed at a DC 18 Constitution saving throw or suffer a -2 penalty to all Strength checks and saving throws. Additionally, creatures who fail the save suffer a -2 penalty to all Strength-based damage rolls. This penalty does not stack. This penalty ends on a long rest, or when the affected creature is cured by a Lesser Restoration spell.
The blooming guardian takes 5 poison damage at the start of its turn as long as it's in Full Bloom. It can end Full Bloom as a bonus action.