With its dual Ghost/Grass typing, Pumpkaboo first made its appearance in Generation VI within the Kalos region
Youve got the obvious answers in vehicle and mount cards, but also mana acceleration, cheating out big spells, racing through your deck with cycling and milling, and sacrificing life or cards to gain tempo (also captured by the one-time boost of exhaust abilities)
Its a good way to refill your hand after a board wipe, and it also has flashback, so you can use this green instant a second time, or after youve discarded it
There must be other forces at play
Choose a commander you enjoy, define a clear strategy, add 7-10 win conditions, add the core components (draw, ramp, removal), build a 36-38 land mana base with color fixing, then playtest and tune the ratio