Because Epic Weeks are celebrations of the site's birthday, the primary healing items take the form of party hats. Party hats can be obtained just by browsing the main site, where they will appear randomly. Sometimes, they will also appear in combat when making attacks.

Consumed on use.
Found randomly while browsing the main site or when making attacks in combat, up to a maximum per day.

Consumed on use.
These generally start appearing about half way through Epic Week; once they become available, they can be found randomly while browsing the main site or when making attacks in combat, much like the standard party hats, and also up to a maximum per day.

Consumed on use.

Consumed on use.

Consumed on use.

Consumed on use.

Consumed on use.

Consumed on use.

Consumed on use.

Consumed on use.

Consumed on use.

Party Hat of Healing
Heals between 5 and 15 HP.Consumed on use.
Found randomly while browsing the main site or when making attacks in combat, up to a maximum per day.

Super Party Hat of Healing
Heals a user for half of their maximum HP (37 when the max is the standard 75.) Additionally restores 1 stamina.Consumed on use.
These generally start appearing about half way through Epic Week; once they become available, they can be found randomly while browsing the main site or when making attacks in combat, much like the standard party hats, and also up to a maximum per day.
Bake Sale Items
Some items that were sold during the 2019 Operation Audacious Phoenix Bake Sale Fundraiser can be consumed for healing during Epic Week. Since these are extremely rare collectors items that generally can't be replaced, and heal for less HP than the free party hats, most people would not consider using them for this purpose. But they are included here for completeness.
Chocolate Chip Cookie
Heals a user for 1 to 4 HP.Consumed on use.

Raspberry Thumbprint Cookie
Heals a user for 1 to 4 HP.Consumed on use.

Rich Cupcake
Heals a user for 1 to 4 HP.Consumed on use.

Strawberry Lemonade Cupcake
Heals a user for 1 to 4 HP.Consumed on use.

Pink Macaroon
Heals a user for 1 to 4 HP.Consumed on use.

Blue Macaroon
Heals a user for 1 to 4 HP.Consumed on use.

Yellow Macaroon
Heals a user for 1 to 4 HP.Consumed on use.

Purple Macaroon
Heals a user for 1 to 4 HP.Consumed on use.

Green Macaroon
Heals a user for 1 to 4 HP.Consumed on use.
Lore Wiki » Epic Weeks » Common Epic Week Features » Healing Items