Tanoshii Muumin Ikka

episodic series for kids about a community of cute creatures and their mischievous shenanigans.  

Both are children's anime and fun to watch. Both are co-production with another country. By coincidence, both have 78 episodes. Moomin is fantasy, while Chiisana Viking Vickie is not. Chiisana Viking Vickie is more cartoonish. 

Fun Iyashikei with very cheerful and charismatic characters. In addition to Moomin taking place much more in spring, autumn and summer, there are also episodes in winter, which reminded me of Heidi. Of course, both are part of my favorite anime. 

Both are fantasy anime and have main characters that are not human. Bosco Daibouken is more Adventure, while Tanoshii Muumin Ikka is Adventure and Slice of Life. 

Relaxing to watch, with good characters and a "mysterious" world. It also has good comedy. Both also have non-standard character designs, which is great. 

If you like episodic anime where you get to learn the philosophy of life of people and their reasons to live like that, please check the other anime. They're excellent adventure iyashikei anime. 

fabulous infantility in the most positive sense... a certain kemono floor on which it is pleasant to look at everyone, and children, and adults 

Relaxing Slice of Life with great character relationships. As much as Figure 17 has a focus on the development of the protagonist and Moomin is an anime that focuses on just being fun, both deal a lot with the relationships that the characters have in their day-to-day lives. 

Old school series for entire family. Slice of live in small valley village. There is more magic and adventure in Muumin. Tanoshii Muumin Ikka is based on books by Tove Jansson and on comics by Tove and Lars Jansson. 

Both are "made for kids but enjoyable by everyone" tales about talking animals with a rare human thrown in. Both are light-hearted and center around a small village's day-to-day activities, but also bring us on a fantastic adventure once in a while ; basically they're both slice of lives with a touch of fantasy, and nature / the outdoors is strongly present in both. While Doubutsu no Mori is only a movie, Tanoshii Muumin Ikka is a long TV series, but I'm a big fan of both for the same reasons. They're equally good if you're looking for something endearing, relaxing and wholesome to watch.  

Both anime want to teach children that the environment and animals are important. In both series, the main characters always want to help others. Ahiru no Quack has a somewhat darker storyline, while Moomin is more cheerful. 

Both are very slow, calming shows with a memorable cast of characters and heart. These shows have a feeling of adventure that allows the viewer to be enthralled even if the pace is a little sluggish. 

These series take place in a valley near a snow covered mountain, where the most important main character lives in a cylinder shaped house. The characters are more or less humanoid creatures. The series cover the daily lives and adventures of the characters in pretty much independent stories, which take place over the 4 seasons (fall, winter, spring, summer). 

Both are about a magical world replete with happy characters, light-heartedness, warmth, childlike innocence, and a carefree joy.  

If you like character driven adventure then I recommend Tanoshii Muumin Ikka. Unlike most series from 90s this series has aged very well because even nowadays anime creators struggle to make believable worlds with characters that feel realistic.. characters that feel like your old friends. Seeing Made in Abyss created similar impression for me. Very well constructed world with charaters that even from first episode are very sympathetic and feel realistic in their motivations and in their character traits.. 

Both are slice of life, children-aimed anime aired in the television when I was a child and had no idea what anime is.