The Health Chest and the Experience Chest

The Health Chest and the Experience Chest
They look a bit like normal chests, but red or green colored, and make heart or exp particles depending on the chest type. They only generate in structures that have enemy mobs, and very rarely in some deep caves randomly.

When interacted with, they burst open and regenerate the player's health, or send lots of EXP flying everywhere. The effect is one time only, and they turn into regular chests afterwards.

The health chests can be very useful in difficult dungeons where you need lots of healing, while the EXP chests work as a satisfying reward, while also making EXP gathering more fun and less grindy without having to rely on mob farms.