Traits

Extremely long horns are rare.
Horns with 3+ colors are Rare, no matter the size.
Multi-pronged horns (3+ prongs) fit into this category, no matter the size.
Multiple pairs of horns fit into this category, no matter the size.
Merged (connected) horns are rare, no matter the size.
Horns growing from oddly placed spots (down the center of head/two on one side/etc), are rare no matter the size. *
*Note, horns must still be growing from the head rather than from elsewhere on the body like arms/back/etc