Grandpa is Ill (or Pingu's Grandpa Is Sick) is the twenty-first episode of the first season.
Pingu is painting a picture while his mother is ironing clothes, but then the telephone rings and Pinga answers the phone whilst on Pingu's shoulders. Mother takes over the phone to discover it is Grandpa (her father) who is suffering from the measles.
They all go to Grandpa’s house and while Mother tries treatments, Pingu and Pinga run around singing and dancing to cheer Grandpa up, but end up giving him a headache. Mother tells them to be quiet, but then they go and fiddle with the sauce pan until the lid falls off. Mother tells them to stop messing about and keep out of the way, so they go over to Grandpa's wardrobe. Pinga plays dress-up and Pingu crashes a sledge into the wardrobe.
Mother makes them go outside, where Pingu finds a board and puts it above a giant wad of snow to make a seesaw. Pingu bounces Pinga up and down on the seesaw making her woop for joy, making Mother run out to tell them to stop the noise. As Mother puts spot cream on Grandpa's head, Pingu and Pinga play kick snowballs at the door. Mother goes out to stop them banging at the door and gets a snowball in the face. This is the last straw for her, so she then tells them to go home.
Pingu and Pinga sledge back to their igloo and then they use red markers to make fake spots on their faces. Then Pingu calls Mother to tell her that they have got Grandpa's measles. Mother zooms straight home to find her children under loads of bed sheets and finds them all spotty. Mother rubs their heads to see how hot they are and she finds out they have tricked her. Mother relieved, she lets Pingu put spots on her face too. She then joins Pinga in jumping on the beds, but when she jumps onto Pingu's bed she smashes it to pieces, which is enough to make a pengiun of any age laugh.
- This is the first time we see Grandpa from Mother's side of the family.
- At one point, when Mother walks away from Grandfather to cook, a frame of animation is skipped.
- Mother should have remembered to go back to Grandpa's after discovering Pingu and Pinga were not really ill.
- When Pingu phones Grandpa's house, Grandpa's telephone moves right next to his front door.