Toon-Us-In was an American-Korean animation studio that animated episodes of The Ren & Stimpy Show, Captain Simian & the Space Monkeys, Watership Down: Home on the Down, some Peanuts specials, and Love Story of Juliet. In addition, they animated the main titles for Hey Arnold!.

Episodes of The Ren & Stimpy Show they animated:

• "Chicken in a Drawer" segment
• Untamed World short after "Hermit Ren"
• "Magical Golden Singing Cheeses"
• "Double Header"
• "My Shiny Friend"
• "Ren Needs Help!"
• "Ol' Blue Nose"
• "City Hicks"
• "Ren's Brain"
• "Who's Stupid Now?"
• "Varicose Veins" segments
• "Pen Pals"
• "Dog Water" and "Craft-Works Corner: Stimpy Kadoogan" segments
• "The Last Temptation"