Oz Squad was a comic book series from the 90s written by Steve Ahlquist, and slightly inspired by superhero comics like Doom Patrol and spy series like Mission Impossible.
Happening in modern day 1990s, Earth and Oz have been connected via magical portals since before WWII. An adult Dorothy is the ambassador from Oz to Earth, and head of a special task force called the Gale Force made of herself, Tin Man, Scarecrow, and Lion who has the ability to change into a fully human form. Dorothy is a crackshot, plus she has the magic belt which gives her nearly omnipotent powers accept on Earth where they're limited. The Gale Force has to deal with a runaway Tik-Tok whose "morality spring" has run down causing him to turn evil. He's later brought back, but then goes on another rampage as a crime boss apparently after becoming accustomed to being evil. Meanwhile, the Wicked Witch of the East who somehow survived having a house dropped on her tries selling the plans to Tik-Tok's mechanics to foreign countries, but Dorothy & Co. stop her. The next story arc becomes one involving time travel where Dorothy, Ozma(who is now Dorothy's wife!), Scarecrow, and Tin Man are all sent back in time to just before the great Witches Rebellion where the witches of all four nations try to stand up to the mad King Pastoria(Ozma's father). Scarecrow is sent further back in time to the Renaissance Period to help Leonardo Da Vinci create the Philosopher's Stone, before eventually making his way back to be reunited with Dorothy and Ozma in late 1800s Oz. Tin Man ends up in a different part of Oz at about the same time, only to see himself as Nick Chopper transformed into a metal man.
This series went on for 10 regular issues, the first 4 by Brave New Words, and then the last 6 were self-published by Patchwork Press. There were also 2 one-shot specials, one of which was Little Oz Squad also by Patchwork Press which had the generic cast as kids in a Little Archie motif. The other was the Oz Squad Special that was printed by Millenium Publications, and was the original concept of what the entire time travel story arc from issues #5-#10 was supposed to be about, but doesn't take place in the regular continuity after that point. The comic featured artwork by Andrew Murphy, Terry Loh, and Mike Sagara. The series was recently reprinted into two annotated graphic novels which are available from Lulu.com in paperback and download, as well as other book dealers like Tumble Tap. Steve Alhlquist has plans to continue this with artist Sean Casey. Oh, and you can find some great original Oz Squad artwork by David Lee Ingersoll who did the cover art for the graphic novels.