An upperclassman practical joker who used to mercilessly torment young Kirk while both were students at SF academy.
He merrily greets Kirk with a big warm welcome...
...Then briskly decks Kirk with a big punch to the jaw.
He taunts Kirk, saying "Plant one on me, just like you always wanted to do!" (Plant what, a kiss?)
Kirk seems delighted! As a matter of fact, he would like to "plant one" on the guy.
Kirk lunges, pouncing upon Finnegan with joyful alacrity, and they grapple...
...But when Yeoman Barrows screams, Jim reflexively rushes off to the rescue, temporarily abandoning Finnegan.
BUT Kirk chases him down again later, so they can finish what they started - a brutal, no-holds-barred, knock-down-drag-out brawl.