Although basically cool and cautious, when it’s caught by surprise, it’s seized by panic.
– Pokémon Moon Pokédex
Decidueye is the fully evolved grass starter of gen 7. Its typing of Grass/Ghost is unique for starters, but there have already been 2 Grass/Ghost families that came before. Despite being based on an owl, it’s not Flying type. However, it is in the Flying egg group, and learns many Flying moves by level-up (though oddly enough, it can’t learn Fly or Aerial Ace by TM).
Its signature move is Spirit Shackle, which is a physical 80 power Ghost type move that prevents foes switching out. It can be upgraded to Sinister Arrow Raid with Decidium Z. Its hidden ability Long Reach allows it to use contact moves without triggering effects caused by contact (such as damage from Iron Barbs, Atk drop from King’s Shield etc).
Stat-wise, its stats are pretty balanced, with Attack being its highest; it also has decent Sp Attack and Sp Def.
Decidueye was added to Pokken Tournament DX as a playable character…. however, Smash Bros Ultimate picked Incineroar over Decidueye 😦