Campestris

Campestris are happy-go-lucky mushroom-like creatures with few cares or worries. They are captivated by music, though they can't distinguish between a well-played performance from a bad one. If anyone plays an instrument or sings in the campestris' vicinity, the little creatures will happily sing along, each in an obnoxiously nasal falsetto, as they dance and caper around whoever is making the music.
Campestris can easily imitate lyrics and music. After a campestri has practised a song or a piece of music three or four times, the creature remembers it forever.
Campestris vary wildly in colour from white to tan to dark brown, but they always have red or purple caps and speckles. A Campestri moves by manipulating the mycelium that grows out of the base out of its stem and supports it. The mushroom creatures eat salty soil, filter out the soil, and excrete a slippery paste of purified soil (stripping of things nourishing to fungi, of course). Eating salt is also a defence mechanism, because it makes the campestris taste salty and thus unpleasant to most creatures, though bullywugs consider them a delicacy.
Found normally in the Feywild, anywhere there is Fey creatures present, there is the chance of Campestris being present too. Seen as a distraction and annoyance by some, they will be driven off if possible by some. This has led to the odd pocket of them found in different regions of Earth having Campestris present.