Den Den is a snail and Keroppi's good friend. He is voiced by Elva Mai Hoover.
Den Den is a brown snail with a blue shell and big eyes.
Den Den is Keroppi's constant companion despite their energy and activity levels. He is laid-back with a penchant for daydreaming, and he loves to play in the rain. He spends a lot of time trying to catch up with Keroppi.
In "Let's Play Baseball", Den Den gives Teru Teru the slow motion replay during the big game when she announces today's game between the Gammas and Keroppies.
In "The Frog's Secret House", he and Teru Teru tell Keroppi and his friends to come out to the Frog House since there was something wrong happening there.
In "Let's Be Friends", before he sets off to visit his family in the forest, he becomes friends with Choro and doesn't get scared of him. After the trip, he introduces Keroleen to Wink and she didn't like him. Later, he and Teru Teru go to Keroleen's house to tell her that the soccer game was on.