Aka gremlins from movie of same name

Mutable appearance:  perks taken effect the killer appearance. 

Power source: mutable demon

Small size. Very hard to see killer as is less then half the size of a survivor. 

Web (adds spider rear to gremlin)
Can slow survivors or block movement.

Flight (adds bat wings)
Allows flight so can move faster and over or through areas faster.

Vegetable ( change appearance adding peppers)
Area effect, blurred vision

Female ( change to female)
Entrance, slow effect when looking at gremlin

Sunlight resistance (change skin color)
Negates all flashlight penalties,  especially gremlin weakness.

Buff gremlin (massive mussels)
Negate most of carry and hook penalties,  one hit pallets.

Weakness
Weak. Weakest grip much easier to break carry.

Longest hook . Takes gremlin the longest to put survivors on hook.

Allergic to sunlight: 
Not only is killer blinded, but also turned to stone for a time.(if carrying survivor,  survivor is unable to escape and wiggle is reset and unable to start until gremlin breaks free.

New survivor : gizmo master
Perk , send gizmo
Gizmo runs off leaving a fake scratch mark trail.

Gizmo helper
Faster heal, generator repair, box search

Not sticking arround
Increased chance to get off hooks. Can attempt to get off hook even in struggle.