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"
"dweller near the heath"
"fire, flame"
"ruler of the army (Scandinavian form)"
"lives near a bridge"
"son of Cole"
"born of fire"
"bold counselor, brave advisor"
"swiftness, fleetness"
"son of Cole"
"son of the south"
"stream, small brook"
"long hill, ridge"
"shield wolf, protector"
"from Sebaste"
"home power, ruler of work"
"lawful, true to one's pledges"
"immortal, divine"
"noble, handsome"
"cheerful, optimistic"
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.