The dwarf who shares his name with one of Yggdrasil’s four stags is Dvalinn.
Dvalinn appears in Norse myth as a dwarf and is also listed among the four stags that feed around Yggdrasil. The other three stags are Dáinn, Duneyrr, and Duraþrór. This unusual duplication reflects the way names and mythic roles can recur across the Poetic Edda and Prose Edda.
The stag Dvalinn is named in Grímnismál, a poem of the Poetic Edda, and in Snorri’s Gylfaginning. The animals are described as feeding on the tree’s branches or foliage, while the dragon Níðhöggr attacks its roots and the squirrel Ratatoskr carries messages up and down its trunk.
The dwarf Dvalinn has a much wider mythic profile. His name is associated with sleep or dormancy, and he appears in dwarf genealogies, legendary forging traditions, and references to runic knowledge. Readers sometimes choose Dáinn because it is another stag’s name, but Dáinn is not the dwarf specified by this question.