This is Season 5 episode 12 "That Sculpture Isn't Yours, It's Mime". Ruff sends Emmie and Marc to learn about mime, and sends Rubye and Jay to make kinetic sculptures.
This is Season 5 episode 11 "'Eureka' is Not a Brand of Dog Food". Ruff sends Emmie and Shreya to make a hovercraft so it will help him move easier. He also sends Marco and Jay to make something that will make his life better.
This is Season 5 episode 3 "You Can't Teach an Orange Dog New Tricks". Ruff sends Marco and Shreya to learn about a mystery animal, and Rubye to learn how to make things disappear.
This is episode 6: "It's Ruff in the Ring". Ruff has accidentally been booked for a boxing match, and needs help. So he sends Shreya to learn how to box, and Marc and Marco to make protective head gear.
This is Season 5 episode 8 "How Much Frosting Can You Bear?" Shreya, Emmie, Marc, and Marco are sent to make a wedding cake for Grandma's friends' humans. Also, Rubye and Jay make a bearproof picnic basket.
This is Season 5 episode 5 "Ruffman Manor is Haunted". Ruff receives an letter saying that he has inherited Ruffman Manor, but believes that there are ghosts haunting it. So he sends the FETCHers to investigate the house.
This is Season 5 episode 10 "Who Wants to Trade for Some Old Tracks". Ruff sends Emmie and Marco to learn about animal tracks, and sends Rubye and Shreya to learn how to trade things.
This is Season 5 episode 9 "The Legend of Ruffman's Gold". Ruff sends Emmie, Marc, and Jay to find gold so Ruff can replace Helga's jewelry that was accidentally covered in tar.