I think in CT, many of them were treated as blade, cutlass, etc. with some sort of mods applied. Animals of modest sizes were rarely a real danger to well equipped mercs, but sometimes to the 'thinky' classes who didn't come loaded up. In larger numbers, or if you have a massive animal (we had an 800 kg one at one point), then they should be very dangerous.

You could go the way that D&D did:

claw/claw/bite

and if you are a feline with back claws, two more. If both hit, they do double damage as this simulates the attempt to disembowel.

Really, Traveller (all variants0 spends a lot of ink on systems for planets, animals, economies, and vehicles/ships, but really all of those are story vehicles, not ends in themselves. If you rule in ways that place your players in peril and provide tension and don't just kill them outright, then your game will be memorable. I used to do all those designs, now I realize I can off the cuff the descriptive colour, make rolls that make sense in where critters or vehicles/ships are part of a scene, and I focus on the story goal that having them there assists.

I had a giant underwater kracken sort of thing that used to 'dry fish' with filaments up onto the beeches. When it caught you, it pulled you underwater. If you had the right gear or could breathe hold a long time, you could then try to free yourself. If not, panic set in fast (in the players, not just their characters). Killing an NPC red shirt is always a classic way to underscorethe danger. The more gross and sudden, the more shocking to players.

You don't usually want the players to die (unless they are wilfully stupid), but you do want them to feel like they might if they weren't really smart and lucky....

TomB