OK here's one my co-narrator told me about his character. This led to the character getting his a** reamed by the NPC CO, and a demotion, but it was funny as heck!
Situation: TNG time, just after Wolf 359. The ship the character is on is an old (movie era) destroyer, pulled out of mothballs to test new anti-Borg weapons systems. They wind up facing off against a Romulan Warbird that has them dead to rights:
Romulan Commander (on screen): I am willing to negotiate the terms of surrender...
PC (playing the Sec Chief/Tac Officer, to CO): Captain, we don't have the facilities to take them all prisoner!
Another time: I stole a gag from Diane Duane. Also earlier in his career, the PC had caught a shapeshifter on board that had assumed the form of a cat. Since, as Sec Chief, it was his job to know what lifeforms were on board, he knew it didn't belong (no one had a cat registered), so he stuned it. Word got around and he got a lot of ribbing for it...
Anyways, the gag: On a colony world, a tribble predator has gotten loose from a zoo, and for lack of natural prey has taken to eating the colonists cats. I assigned the task of recapturing the TP to the PC's ship (different ship, and the PC was now the CO).
They beam down and commence t' huntin'...I tried to play it suspenseful and a bit creepy, and sure enough, when I announced that a blurry form leaped at him from a tree...ZAP!
I waited a beat (mostly because I couldn't believe it had worked), and announced: "OK, an unconscious cat falls to the ground at your feet."
The PC did a slow mo "DOH!", shaking his head. Then I played my trump card: the colony governor's little girl, out searching for her missing cat, shows up. (best "little girl" voice) "Mister Captain...why did you shoot Fluffy?"
Later, when he was pulling a stint as temp Commandant at the Academy, he had to break up a fight between a squad of Caitian cadets and a squad of Agorites (a caninoid race I made up for the occasion).
Later still, I saddled him with a horde of Caitian officers (well, only 15 or so, but they tended to hang out together, were mostly males, and I play Caitians as a bit more "boisterous" than normal). He got so tired of them, he pulled into the nearest Starbase and summarily ordered them off the ship. It became known as the "night he put the cats out".
The co-narrator got his revenge the other day, though. My PC, a Betazoid Science Officer, was beaming down to a colony that had been razed by an unknown (at the time) force. My PC was the youngest of the group, and a bit nervous. So when a blurry form leaped out of the bushes at him...you guessed it: ZAP!
The co-nar's character (same one as above) looked down at the stunned cat at my character's feet and announced "Welcome to the club, Mr. Kell..."