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.