Snufkin Departs on a Journey
For no special reason Moomin wakes up in the middle of winter and can't go back to sleep. This is quite unheard-of. He is unable to wake the others, and finally, shivering, he makes his way outside into the bleak, unfamiliar whiteness. He meets Little My, who has woken up even before him, and Too-tick who lives in the bath-house. He meets the invisible mice, who also stays there for winter, and he almost meets the Lady of the Cold, the most fearsome of all winter's manifestations...
Aired 06/09/1990EP 21 - Snufkin Departs on a Journey

Moomin
In the remote and mysterious Moomin Valley live the Moomin trolls, gentle and peaceful creatures. Young Moomin and his family experience many strange adventures, both magical and mundane. Based on the children's stories by Tove Jansson.
(Source: Anime News Network)