Legendary class and legendary traits
only legendary leech monsters have these
Mythical traits only obtained by using uncommon mythical upgrades
Mythical traits only obtained by using common mythical upgrades
Traits obtained through the use of shop items.
Saltwater class/saltwater traits
Usually only saltwater leeches can have these traits, but on rare ocassions or by using special items normal leeches can have them as well.
Normal traits anyone can use
Traits that are not listed on the trait sheets, only obtainable through special means.