query: #dragon / serpent artworks in Wikidata
  SELECT DISTINCT ?item ?itemLabel ?creator ?creatorLabel 
  WHERE 
  {
    ?item wdt:P170 ?creator.    # creator of work
    {?item wdt:P180 wd:Q1254187.} # depicts a dragon 
    UNION {?item wdt:P180 wd:Q2102.} # depicts a serpent 
           .
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }
  ORDER BY ?creatorLabel