This is a response to the general question about druids and magical items. (My next response focuses on magical items during wild shape.)
TBH there aren't a lot of great magic items for druids in general. The fact that the best magic item for a druid is staff of the woodlands and the best magic item for a wizard is staff of the magi shows just how undervalued druids are compared to other spellcasters. Because WoTC hasn't added any good magic items for druids since 5e was created leads me to believe that people need to homebrew their own magic items, which is unfortunate. I like the core and homebrew ideas offered above.
That said, here are the magic items sought by my druid:
Capstone items: Wand of the War Mage, Amulet of the planes, Rod of absorption, Staff of thunder & lightning, (Half) Dragon scale mail
Staff/Rod/Wands: Wand of the War Mage (+1-3 to spell attack ROLLS) Staff of thunder & lightning Staff Of Swarming Insects Staff of fire/frost
For Defense: Dragon scale mail (14 base AC, + magical bonus) Animated shield, Sentinel Shield, Cloak of displacement, Amulet of the devout (bonus to spell attack rolls, and saving throw DC) Barrier tattoo (+1-3 to AC, saving throws) Ioun Stone Insight (+2 to Wisdom, 20 max) Ioun Stone of Mastery (+1 to proficiency bonus) The Book Of Exalted Deeds (+2 to Wisdom) Belt of Dwarvenkind (+2 increase to Constitution, advantage on Charisma checks against dwarves, Dark Vision, knowledge of Dwarvish, resistance against poison, and advantage on saving throws against poison)
For Spells: Ring of spell storing Pearl of Power (restore spell slots)
Wild shape is the main focus of the Moon subclass, so I assume you're asking about magic items that a Moon druid can use during WS. I'm ordering the options I'm giving from the most plausible to less plausible.
First, WS RAW state:
You choose whether your equipment falls to the ground in your space, merges into your new form, or is worn by it. Worn equipment functions as normal, but the DM decides whether it is practical for the new form to wear a piece of equipment, based on the creature’s shape and size. Your equipment doesn’t change size or shape to match the new form, and any equipment that the new form can’t wear must either fall to the ground or merge with it. Equipment that merges with the form has no effect until you leave the form.
That is, equipment can be worn during WS if the size or shape can be worn by the WS form. Many DMs allow PCs to wear rings around their necks on a strip of leather instead of on their finger. So you should be able to wear a magic item around your neck on a piece of leather or rope such as a ring as long as it is large enough to fit around the neck of the beast you WS into, e.g., a bear.
Second, there are magic magic items that don't need to be worn or held, which should be able to benefit a druid during WS:
Animated shield - note that you'd have to animate the shield before transforming into WS
Ioun stone - there are 20 ioun stones, some give +2 to Constitution
Third, magical tattoos. It's a stretch to call a tattoo (a piece of) equipment. It doesn't make much sense for a tattoo to "fall to the ground" while transforming into WS. One could argue, however, that a tattoo merges into the WS form. So, magical tattoos require a convo with your DM.
Last, there are other ways besides using magical items that can benefit a druid during WS. The way to get the most out of WS is to cast a spell before WS. Some spells require concentration, so Moon druids should boost their Constitution as much as possible, i.e., during ASI opportunities, feats, etc. The spell that is is often mentioned is the 3rd level spell Call Lightning, which has a duration of 10 minutes, but requires concentration. But one spell that that is available to druids at 2nd level that lasts much longer and doesn't require concentration is Wild Companion (i.e., Find Familiar). The wild companion can then take the Help action, which gives the druid (or any single member of the party) advantage on attack rolls. If your companion is a giant owl (CR 1/4), they have the Flyby feature, which protects them from opportunity attacks.
This is a response to the general question about druids and magical items. (My next response focuses on magical items during wild shape.)
TBH there aren't a lot of great magic items for druids in general. The fact that the best magic item for a druid is staff of the woodlands and the best magic item for a wizard is staff of the magi shows just how undervalued druids are compared to other spellcasters. Because WoTC hasn't added any good magic items for druids since 5e was created leads me to believe that people need to homebrew their own magic items, which is unfortunate. I like the core and homebrew ideas offered above.
That said, here are the magic items sought by my druid:
Capstone items: Wand of the War Mage, Amulet of the planes, Rod of absorption, Staff of thunder & lightning, (Half) Dragon scale mail
Staff/Rod/Wands: Wand of the War Mage (+1-3 to spell attack ROLLS) Staff of thunder & lightning Staff Of Swarming Insects Staff of fire/frost
For Defense: Dragon scale mail (14 base AC, + magical bonus) Animated shield, Sentinel Shield, Cloak of displacement, Amulet of the devout (bonus to spell attack rolls, and saving throw DC) Barrier tattoo (+1-3 to AC, saving throws) Ioun Stone Insight (+2 to Wisdom, 20 max) Ioun Stone of Mastery (+1 to proficiency bonus) The Book Of Exalted Deeds (+2 to Wisdom) Belt of Dwarvenkind (+2 increase to Constitution, advantage on Charisma checks against dwarves, Dark Vision, knowledge of Dwarvish, resistance against poison, and advantage on saving throws against poison)
For Spells: Ring of spell storing Pearl of Power (restore spell slots)
Started playing 1e in the late 70s and stopped in the mid-80s. Started immersing myself into 5e in the last year.
Wild shape is the main focus of the Moon subclass, so I assume you're asking about magic items that a Moon druid can use during WS. I'm ordering the options I'm giving from the most plausible to less plausible.
First, WS RAW state:
That is, equipment can be worn during WS if the size or shape can be worn by the WS form. Many DMs allow PCs to wear rings around their necks on a strip of leather instead of on their finger. So you should be able to wear a magic item around your neck on a piece of leather or rope such as a ring as long as it is large enough to fit around the neck of the beast you WS into, e.g., a bear.
Second, there are magic magic items that don't need to be worn or held, which should be able to benefit a druid during WS:
Third, magical tattoos. It's a stretch to call a tattoo (a piece of) equipment. It doesn't make much sense for a tattoo to "fall to the ground" while transforming into WS. One could argue, however, that a tattoo merges into the WS form. So, magical tattoos require a convo with your DM.
Last, there are other ways besides using magical items that can benefit a druid during WS. The way to get the most out of WS is to cast a spell before WS. Some spells require concentration, so Moon druids should boost their Constitution as much as possible, i.e., during ASI opportunities, feats, etc. The spell that is is often mentioned is the 3rd level spell Call Lightning, which has a duration of 10 minutes, but requires concentration. But one spell that that is available to druids at 2nd level that lasts much longer and doesn't require concentration is Wild Companion (i.e., Find Familiar). The wild companion can then take the Help action, which gives the druid (or any single member of the party) advantage on attack rolls. If your companion is a giant owl (CR 1/4), they have the Flyby feature, which protects them from opportunity attacks.
Started playing 1e in the late 70s and stopped in the mid-80s. Started immersing myself into 5e in the last year.