My dad was growing some peppers. And one of them was a week of having fully grown peppers, but something had eaten it. It ripped of all the buds, peppers and leaf's of and left them on the soil in the pot.

I live in middle Europe

Hi Aleksandar, and welcome to garden.org

That's a shame about your dad's pepper plant! It was most likely some critters like squirrels, rats, or a flock of birds, to do that kind of damage. Do you know if the damage happened at night or in the daytime? Were any of the other plants damaged? If he still has plants with peppers coming along, I'd recommend you build some kind of small cage to go over the plants. Chicken wire is the most reasonable stuff here to protect plants but still let in the sunlight.

I have a lot of birds and animals visit my garden, but the only ones that I've known to do that kind of damage to plants are the flocks of hooded parakeets. When I see them I rush out and chase them off - luckily they make a lot of noise so I usually know when they are there. Not sure if you would have these where you are, but the ones here are not native birds, they are pets that have escaped and 'naturalized' and they migrate to warmer areas in the winter.

My cat would happily destroy your pepper plant. Given the chance, she will eat it down to the soil line. Peppers, even hot ones, seem to be tasty to a wide range of critters.