A Few Simple 5e Magic Items

Acid Arrow Bow
Weapon (longbow), very rare (requires attunement)
Any arrow shot with this bow magically transforms as it leaves the bow’s string into a magical acid arrow. On a hit, the target takes 1d8 acid damage immediately and 1d4 acid damage at the end of its next turn. On a miss, the arrow splashes the target for 1d4 acid damage immediately but no damage at the end of its next turn.

Lantern (Hooded) of Alarm
Wondrous Item, very rare
This lantern burns regular oil, but when anything or any creature not already in the light (bright or dim) breaks the boundaries of its dim light it rings a bell like alarm capable of waking someone asleep in the bright light area. The alarm continues to ring until the lantern is touched. It may be used once per day for 8 hours.

Necklace of Arcane Eyes
Wondrous Item, very rare (requires attunement)
This necklace typically has 20 eyes attached. As an action, you can remove an eye and release it. It will turn invisible and hover for 1 hour. As long as you wear the necklace, you mentally receive visual information from the eye, which has normal vision and darkvision out to 30 feet. The eye can look in every direction.

As an action, you can move the eye up to 30 feet in any direction. There is no limit to how far away from you the eye can move, but it can’t enter another plane of existence. A solid barrier blocks the eye’s movement, but the eye can pass through an opening as small as 1 inch in diameter. Only one eye can be active. If another eye is released, the prior eye winks out of existence, as it also does when one hour expires.

Once all eyes are used, the necklace loses all magical properties.

Awakening Medallion
Wondrous Item, very rare
You place this medallion on a Huge or smaller beast or plant. The target must have either no Intelligence score or an Intelligence of 3 or less. It fuses with the target and the target gains an Intelligence of 10. The target also gains the ability to speak one language you know. If the target is a plant, it gains the ability to move its limbs, roots, vines, creepers, and so forth, and it gains senses similar to a human’s. The GM chooses statistics appropriate for the awakened plant, such as the statistics for the awakened shrub or awakened tree.

The awakened beast or plant is charmed by you for 30 days or until you or your companions do anything harmful to it. When the charmed condition ends, the awakened creature chooses whether to remain friendly to you, based on how you treated it while it was charmed.