This is from my first campaign and I remember it clear as day because it was the first time a nat 20 saved my ass big time.

The party wizard and I were exploring an abandoned building in town and we were attacked by a large rat which I tried not to kill but I bit the wizard and nearly killed him so he used thunder wave and rolled max damage. Unfortunately it was also enough structure damage for the building to collapse and it was loud enough that the entire town came outside to see wtf just happened.

Now our wizard didn’t protect me from this spell so I’m basically deaf and nearly dead. Upon seeing this gathering of villagers I try to cover our ass and shouted “THERE WAS A MIMIC!!”. I rolled a nat 20 for deception and after that we were treated very well by the villagers