Mutations

Common
overgrown fur
visible canine teeth / overgrown fangs

Uncommon
goatee
sprouts
horns
mane
antennae
long claws

Rare
flowers
hairless
halo
wings (feathered, dragon, etc)
patchwork
goat horns

Legendary
stars
slimy
globe head
globe body parts
unicorn horn
wings on head
bioluminescence

Seasonal
aquatic mane (Summer)
pool floaties (Summer)
antlers (Winter)
hooves on back legs (Winter)
butterfly / insect wings (Spring)
candy corn horns (Fall)
pumpkin head (Fall)
skeletal parts (Fall)
mouth pincers (Fall)