This creature looks like a dark storm cloud, with sparks suggesting eyes and long sweeping arms charged with bolts of lightning.
Huge Lightning Elemental
Speed fly 100 ft. (perfect)
Melee 2 slams +16 (2d6+5 plus 1d8 electricity)
Space 15 ft.; Reach 15 ft.
Special Attacks metal mastery, spark leap
Str 20, Dex 27, Con 16, Int 6, Wis 11, Cha 11
Base Atk +10; CMB +17; CMD 36
Feats Dodge, Flyby Attack, Improved Initiative, Iron Will, Mobility, Weapon FinesseB
Skills Acrobatics +21, Escape Artist +21, Fly +12, Knowledge (planes) +11, Perception +13
A lightning elemental gains a +3 bonus on attack rolls if its opponent is wearing metal armor, is wielding a metal weapon, or is made of metal (such as an iron golem).
Environment any (Plane of Air)
Organization solitary, pair, or gang (3–8)
Though most think of the Plane of Air as a vast expanse of clear sky, that plane also holds the power of the storm, including monstrous hurricanes larger than entire worlds and thunderstorms whose peals and claps can shatter stone. Whether lightning elementals are the by-product of common air elementals spending too much time near these electrically charged storms or are merely calved off like forgotten flurries, they are aggressive and almost suicidal in their willingness to leap into battle. They particularly enjoy attacking creatures that are made of metal and creatures that wear metal armor or wield metal weapons.
Many lightning elementals have a roughly humanoid shape, but some prefer animalistic shapes (particularly birds and dragons), and a few appear to be nothing more than large disembodied heads made of dark clouds with flickering lightning tongues. Regardless of the shape a lightning elemental takes, the air around the creature hums and throbs with the promise of electrocution and the tangy stink of ozone.
Pathfinder Roleplaying Game Bestiary 2, © 2010, Paizo Publishing, LLC; Authors Wolfgang Baur, Jason Bulmahn, Adam Daigle, Graeme Davis, Crystal Frasier, Joshua J. Frost, Tim Hitchcock, Brandon Hodge, James Jacobs, Steve Kenson, Hal MacLean, Martin Mason, Rob McCreary, Erik Mona, Jason Nelson, Patrick Renie, Sean K Reynolds, F. Wesley Schneider, Owen K.C. Stephens, James L. Sutter, Russ Taylor, and Greg A. Vaughan, based on material by Jonathan Tweet, Monte Cook, and Skip Williams.