You can't really judge a book by its cover -- or a kitty by its puffy fur. My younger cat, Michelle Lynne (1 year old 5.8 kg) is roughly twice as big as her mother (roughly 2 years old, 4.2 kg), but she grew up very sheltered indoors.
Our two cats have a small outdoor enclosure all to themselves where they can sunbathe, jump and play around and do cat things. The enclosure is escape proof, but it also has an open roof area -- which we'll have to fix soon.
Last night, I heard some foreign rustling in the area and saw that a stranger, a black and white outdoor cat had fallen from the roof and into the enclosure -- where Michelle Lynne was happily playing with the insects. The cat frantically scrambled about trying to find a way to escape -- to no avail. I immediately ran to check the situation and saw that my other cat, Misha had her fur all puffed up and was ready to fight. So I had to grab her and put her in my room temporarily. The problem is that with the stray cat running all around, I couldn't find Michelle Lynne.
After a bit of searching, I found her underneath the bed in what has effectively become our guest room -- shivering in fear and curled up into a ball and right next to her a few meters away was the stray cat, also shivering and curled up into a ball. Fortunately, I managed to call Michelle Lynne towards me and I carried her into my room to be together with her mother. After that, I opened up the front door to let the stray cat out.
When I came back to check on our cats, I saw that Michelle Lynne was still shivering in fear while her mother was licking her all over trying to console her.
It took her until the next day to get over her fear of even coming near the enclosure for fear of another stray cat falling in from out of nowhere. What's funny is that she's literally the biggest cat in the neighborhood and my mother and I would often talk about how she could easily smother any of the outdoor strays if she ever got into a fight with them.
Turns out she's still just a big baby and isn't really meant to be a fighter... her mother, Misha however, is a different story. She was an outdoor cat before we adopted her and we'd seen her easily dominate much larger males in an all out fight before... now she's also a beeg kitty and would probably be even fiercer in a hypothetical catfight. Fortunately, she won't be getting into any. Not on my watch.