This may have been more appropriate to ask before I created this, but, could I have done this in Illustrator? Or did I have to use Photoshop?

This is very interesting Illustration...In Mixed media contest u can use software that u like, such as 3D software's, Illustrator or similar....For better understand the rules u can contact some of the Mod's...best of luck

Could have been made in PS or Illustrator.

The rodent in front is adorable

great source find, and blending..gud luck

Ha-ha-ha, super cool

thanks for the feedback

The lighting is very discordant between the woman and the background, it looks like a bad studio set up. The shadows on the model are far darker than the background, and the dark edge along the bottom of the image just emphasizes the discrepancy. Perhaps you can adjust the levels on the woman to brighten her up a bit, or find a "moodier" background that is as dark and heavily shadowed as she is.

Are you saying all the rest of the source pics are your images? You need to place them UNCUT in the SBS.
Step 2 "vampire" only shows a tree.

what a really neat creation, very fun visual

Just beautiful, I am so amazed by the talent I see ... what a wonderful piece. Good Luck!

Thank you! Honestly I was amazed it came out so good. It started out very rough.

Dramatic result—and a demonstration that it helps to start with a picture with dramatic elements if you're not going to be adding elements from other photos.

How u did Cartoon book effect....?