Schmetterling may be semantically linked to butterfly via 'batter-fly' (beater-fly)
also:
motyl~moth sommerfugl~summer-fly
interesting that wiktionary for papillon shows a puppy :) might also be linked to big pupils and fake eyes
No, it's semantically linked via 'butter'. Schmetterling comes from Schmetten or Schmand which is a sort of heavy cream. There used to be a folk believe that butterflies would consume milk or butter if left uncovered. They were also sometimes called Milkdieb or milk-thief in German.
See: www.etymonline.com/index.php?search=butterfly
Is "smetana" a false friend?
Adds a little too, looks like the idea of butterflies stealing butter may come from their voids looking like butter.
I'd also like to imagine a story being made about them stealing butter to encourage children to cover the butter.
Butter + Schmetten/смета́на • (smetána) probably still come from beat:schmettern<>smith and or smeltan:smelt.
Where do Schmeissfliege (blowfly) and Schmalz(molten fat) sit? ;)
I think the papillon dog breed has big, butterfly-like ears!