Marshmellow is a misspelling of Marshmallow — the correct form uses an A in the final syllable, from the plant Althaea officinalis (marsh mallow) that was originally used to make the confection. The registry carries the misspelled version with 46 records, which is consistent with both common spelling error and deliberate stylistic preference. Either way, the intended meaning is clear: something soft, white, and sweet.
Food Names for Fluffy Pets
Food-based names cluster heavily on light-colored, fluffy animals: Marshmallow (in both spellings), Biscuit, Mochi, Noodle. The naming logic is visual and tactile — the pet's appearance or texture is being compared to the food. A white Bichon Frise or a fluffy white Samoyed named Marshmellow (or Marshmallow) has been given an honest descriptor with maximum sweetness.
The Spelling as a Choice
Whether Marshmellow's E is an error or a preference is genuinely unknowable from registry data alone. Some owners choose variant spellings deliberately to create distinction; others simply don't notice. The name functions identically in either case — the pronunciation doesn't change, and strangers at the dog park won't be checking the spelling.
Counter-Reading: The Length Problem
Marshmellow is four syllables, which is long enough that daily use will almost certainly produce a shortened form: Marsh, Mellow, or simply "the fluffy one." Owners who want to use the full name consistently will need to commit to it intentionally. The two-syllable version Mellow delivers the same soft energy with less syllable overhead.