Molotabby ⟶ (Pulsating Pustule) Hellion
#091 - Molotabby
They can produce a wide variety of acids and reactive chemicals to use neat, or combine into new and exciting forms. They steal glassware from humans; some researchers say they can make their own, but not very well.
Base Stats: 50/100/50/100/50/100 (450)
Ability: Technician/Anticipation/[Broken Glass](Pokemon slowly fills the arena with glass hazards from its broken potion receptacles)
Moveset: Scratch, Growl, Acid, Acid Breath, Acid Claw, Acid Spray, Bite, Toxic, Night Slash, Venom Drench, Foul Play, Toxic Spikes, Haze, Acid Spit, Caustic Mines, Defense Potion, Strength Potion, Healing Potion, Mystery Potion, Acid Cocktail, Chemical Burn, Potent Potable
#092 - Hellion
Its acid is incredibly potent, melting through steel, sand, and brick. It reacts exothermically, leaving behind a dangerous red-hot sludge. It smells awful, too. One Hellion can clear out a whole town.
Base Stats: 100/50/100/50/100/50 (450)
Ability: Aftermath/Stench/[Pustule Explosion](strong hits cause the sacs on this pokemon to explode, dealing damage to the foe)
Moveset: Selfdestruct, Explosion, Ember, Flamethrower, Blast Burn, Eruption, Overheat, Fire Blast, Poison Gas, Smog, Sludge Bomb, Stockpile/Swallow/Spit Up, Amnesia, Caustic Surge, Caustic Wave, Mordant Blast, Vitriolic Slash, Vitriol Beam, Stench Bomb, Chimney Sweep, Combustion, Firefield, Acid Rain, Stinging Cloud, Hellfire, Fumigation, Acid Armor, Acid Burst
These guys have gone through a lot of changes over the years-- Hellion was mentioned but not described in the original Gods and Demons, but at that time it was intended to be a black and red demon TLK lion, basically. lol
The pokedex card quotes are from Things I Won't Work With, a supremely entertaining chemistry blog.
Hellion does of course have a touch of a StarCraft reference in its design.