Male Trill given name based on “John”: Jon
Random Trill family names: Payal, Kunev, Kectan
Random Trill symbiont names: Lahn, Ral, Okiz
Some more alien names based on “John”:
Whiphid: Jon
Gamorrean: Jong
Chiss: Jawn
Fremen: Jonnar
Ewok: Chond
Vulcan: Shon