Mickey, Minnie, Donald, Daisy, Goofy and Pluto all meet in New 60th outfits around the flagpole area in DL. We found that most any given time from open till the parade there are 5 of them out. They rotate from place to place. Only Mickey had a photographer
At DCA we found Minnie, Mickey, Chip and Dale were out in roaring 20s type outfits.
Majority of the characters we found were roaming and had no set schedule. They don't track characters out there like they do at WDW for that reason. Most meet without handlers too, they just walk around.
There are a few set characters that are shown on the times guides but we found most randomly
This should not be an indication of who you will find, just who we saw. No roaming character has a photographer
We ran in to roaming around
Mary Poppins and Bert
Bert alone
Peter Pan
Alice and Mad Hatter
Mad Hatter alone
Cruela D'ville
Evil Queen
Hook
Ariel, Rapunzel and Merida were all spotted in front, just beyond the gates, before you head under the train station tunnels
Tink's nook in DL is fun too. We met Tink, Rosetta and Iridesa. I believe Silvermist had been there at some point that day too. Oh, and Fawn. So you never know who may be in there. They met separate and we found only Tink had a photographer
Over in DCA you can meet Minnie, Mickey and Chip/Dale in fun Roaring 20's type outfits. And as mentioned above, Oswald is there too. We didn't see any roaming characters there. Toy Story characters had a spot over in Paradise Pier. Pluto was also in Grizzly Area, near Soarin. Russell and Dug came out in the Wilderness Explorer area. Some had photographers and some did not