Angry Druid is upset with urban sprawl - what would happen?

[Cikomyr]

If you want just an evil plot that the PCs are going to thwart, then go with the above examples. Very good cases.

But if you want a more.. pragmatic setting for worldbuilding, then how about the Druid gets savvy and manage to organize some sort of.. covenant with the City Council/local lord? The city will have natural parks and areas that would be under the protection of selected rangers in order to house some wildlife, and in exchange the druids always provide their services to limit vermin infestation and disease control; both problems that commonly plagued Middle-Age cities.

Certain provisions might be made for times of famines (where a certain number of the park's wildlife may he used to provide for food), etc.. You could create an entire culture around that Urban Druid covenant.

[Coidzor]

How does any of that prevent a team of equal leveled adventurers from going on a seek and destroy mission vs. the obviously evil druid? Given most teams of adventurers contain a cleric and a wizard, he can't rely on his tier 1 status to save himself either.

Because somewhere in phase 1, people just put a bounty on the druid, and then he's just somebody's XP for their next level up. If the druid is genre savvy, he knows a team of adventurers will be coming for his head and XP the minute he starts making a nuisance of himself.

Unless I misread the OP, the intention was to get a team or teams of adventurers out chasing after the Druid.

[Fable Wright]

How does any of that prevent a team of equal leveled adventurers from going on a seek and destroy mission vs. the obviously evil druid? Given most teams of adventurers contain a cleric and a wizard, he can't rely on his tier 1 status to save himself either.

Because somewhere in phase 1, people just put a bounty on the druid, and then he's just somebody's XP for their next level up. If the druid is genre savvy, he knows a team of adventurers will be coming for his head and XP the minute he starts making a nuisance of himself.

As Coidzor said, the plan was to run this so that adventurers do get involved. And as to why no one's managed to kill him yet? Trackless Step as a class feature, Wild Shape to shake pursuit and grant anonymity, a daily loadout of battlefield control spells to allow for escape, and sticking to small towns that wouldn't have the funds to hire a scry & die kill team. If he does hit larger towns, the druid just sticks in lead-lined bunkers or hijacked Private Sanctums while he's not in the field, and in the field he has a constant Tree Stride up and stays in Crow form in the midst of a Murder of Crows. Scry & die is much less effective when you have to hit your target with AoE spells and they can teleport away to an unscryable tree at a moment's notice.

[sleepyphoenixx]

Scry & die is also pretty unreliable if all your scrying shows is a patch of forest. And that's assuming you can reliably get past the druids high will save to succeed at scrying in the first place.
Catching a properly paranoid druid in the forest is incredibly hard. The DM pretty much has to hand him the idiot ball for a party to have a chance unless they find something he needs to defend.