Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tearjerker: The Thing (1982)
the deaths of the dogs toward the beginning, and later, Clark's reaction to the deaths of the remaining dogs.
Particularly the dog who made an attempt to free itself by biting through the kennel wire, and gets doused with acid for it's trouble. When The Thing starts to absorb the dogs, we see it's fur and skin is mostly burned away, but it's still alive.
When they first see the thing in the dog kennel and start shooting at it, Clark only seems concerned that they're hitting the dogs and even tries to run into the cage to save them despite the fact that doing so would obviously get him killed.