Green herons are indeed green, or at least appear so via some kind of iridescence when they're hit by sunlight. You don't typically think of finding herons in a tree, but in a tree is precisely where these two were. I believe this is a male and female pair but I don't know enough to be sure.
They have quite an extensible neck, but when they're just sitting around and not pecking at anything they usually keep it retracted like this. It makes them look like any other songbird until you notice the long legs and the bodaciousness of that beak.
Bonus picture of this one having a floof:
