Passive skill
The passive skill is a special ability of a creature. Passive skills are always costless and are used automatically. Unless active skills, they cannot be lobotomized, and apart from airborne skill they cannot be removed at all. When playing, you can see passive skills of a creature when you hover the mouse on the card placed on the playing field.
Airborne
Airborne skill empowers a creature to go through Wings shield, and provides protection against guard skill. Since dragons are all airborne, every element has at least one airborne creature.
Burrow
Though burrow ability is mainly an active skill, some creatures like Graboid and mutants may have burrow passive skill. When it is a passive skill, burrow simply means that the creature cannot be targeted.
Ranged
Ranged skill is similar to airborne skill, but weapons own it (Short Bow, Owl's Eye), and makes possible to them to go through Wings shield even when they are not flying.
