It would be great to see these guys randomly spawn as part of the Background Battlefield chaos, but when you get a Quest to vanquish them you don't have to rely on the random Boss determination in Garden Ops to provide the opportunity.
If you've played through the L.E.A.F. Agent Quests previously you can play them again at any point and in the Dave-Bot-3000 Quest of Fireworks of the Ancients you will face off against the Zen Sensei. In the Agent Rose Quest The Wand of Sweet Spells your Boss fight will be with Baron Von Bats.
Because those Quests are structured specifically you'll face those particular Bosses every time you play through and the missions have the bonus of being shorter than your typical Garden Ops run through.
Yeah- it seems like ages ago.
The only reason I still remember them is that my son loves to go back through those early missions and his favorite is to take on Von Bats and his vampire zombie horde.
