It was about a month ago. Around 11/12 pm, I was playing games on my computer and had an open window ( I live on the 3rd floor). My two cats were sitting in it like they always do when suddenly both of them started acting weird. One completely ran out of the room and the second one came to me and started meowing very loud. I brushed it off as maybe they got scared of some car or a bat since there are a lot of them in my area.   
Around 5 minutes after that, I started hearing dogs barking, it's not unusual since there are a lot of them on my street, but it wasn't just a few it was all of them that were barking and that was concerning but since I was playing I didn't want to get up, I knew that all of my animals are at home so I wasn't paying that much attention. But then I heard the scariest sound I ever heard. It was something between barking and howling but it was so low and harsh that it came out of hell it also kinda sounded like a scream. I don't even know how to describe it but it definitely wasn't a normal dog. 
At that moment I completely froze, I was too scared to move but after a few seconds, I ran to my parent's bedroom and saw that both of them get woken up by this sound. Seeing that they both heard that it was not only my imagination, it was like a cold bucket of water thrown on my body.  I immediately ran to the window to look at that creature but only saw the back of it. It was something dog-like but it was HUGE. For the sake of my mental health, I convinced myself that it was a wolf that wandered off out of the woods. 
I heard dogs barking on the whole street for the next 2 or 3 hours as I was still standing in the window hoping it would come back and I could see what it was but it never did.
Since then we have been scared to go out after dark even if our yard is fenced. We used to let our dog stay outside if the night was warm but now we always get home before it gets dark. 

I think it's important to say that I live in a small city. There are a lot of houses around my street but there is also a forest nearby but there is no direct access to it so if it came out of the woods it had to get through someone's garden. And looking at the barking it had to be somewhere close to my home...