Casper sits next to 3 phonetic neighbors — Jasper, Gaspar, and Caspar are the closest matches by sound. Most share Casper's Dutch-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"treasurer, keeper of treasure"
"land of Eoghan (short for Tyrone)"
"spiritually reborn through baptism"
"stone clearing, rocky glade"
"son of Bron"
"praise"
"long hill, ridge"
"oak grove, great"
"great"
"one who catches fish"
"valley, hollow"
"acquired, possessed"
"shield wolf, protector"
"heathland, open moorland"
"small songbird"
"noble eagle (adal + aro)"
"from the Eider river"
"short form of Wesley or Weston"
"of the Julian family"
"crow, raven"
"the cleansing one"
Similar sound: These names share phonetic patterns with Casper — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Persian origins, giving them the same cultural heritage as Casper.
Rhythm: Casper is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.