NeoArkadia(Don't disrespect the Doctor of the Dueling Arts.)
Crowler's event is fairly similar to most of these events: Pick up the event Item from Duelists and use them to face Crowler. Beat Crowler in Duels to earn swag and...
ultimately Crowler himself, along with an Ultra Rare copy of his ace monster, the legendary Ancient Gear Golem.
Dr. Vellian Crowler's Skills
Middle Age Mechs (Level 4)
Begin Duel with the Continuous Spell "Ancient Gear Castle" activated.
Beatdown! (Level 13)
Boosts the ATK of face-up attack position monsters you control by 300 per level 5 or more monsters you control. You can only use the skill once per turn.
Draw Sense: Earth (Level 20)
Can be used each time your Life Points decease by 1500. In the Draw Phase, instead of doing a normal draw, draw a random EARTH attribute monster.
Teacherly Discipline (Drop)
Can be used each time your Life Points decrease by 1500. Declare a Monster, Spell, or Trap Card. That type of card will be randomly selected from your opponent's Deck and placed on top of their Deck. Neither player will see what the card is. Nothing will be placed on top of your opponent's Deck if the declared card type is not in their Deck.
Crowler's Starting Deck:
1 Ancient Gear Golem
3 Ancient Gear
3 Karakuri Spider
3 Giant Mech-Soldier
3 Mighty Guard
3 Shovel Crusher
3 Holograh
1 Machine Conversion Factory
Level 40 Crowler Drops
Crowler Level Up Rewards:
Level 3: Ancient Gear Soldier
Level 4: Middle Gear Mechs (Skill)
Level 7: Ancient Gear Cannon
Level 10: Ancient Gear Beast
Level 11: Ancient Gear Tank
Level 13: Beatdown! (Skill)
Level 14: Ancient Gear Castle
Level 16: Ancient Gear Soldier
Level 18: Ancient Gear Cannon
Level 20: Draw Sense: Earth (Skill)
Level 21: Ancient Gear Engineer
Level 23: Ancient Gear Fist
Level 25: Ancient Gear Box
Level 33: Ancient Gear Explosive
Level 35: Ancient Gear Golem
Level 38: Ancient Gear Knight
Level 40: Spell Gear