Worst thig I've done in the Sims 4? This was back around 2016/2017 when I still had the free time and when the game had less bugs to deal with:
When the Tragic Clown was added: When new things are added to the game townies you meet seem to often have an angry, flirty or sad moodlet. Well, in my curiosity to see how they implemented the Tragic Clown back into the game. It was pretty disappointing to find it wasn't a fixed character (Sonny, male, pale, thin, water phobia) like in the previous games. Also, why would anyone want to play as the Tragic Clown? Well, I found a wonderful purpose after meeting my first Tragic Clown.
Female, had really bad traits and was rude to my Sims. She had to go. I added her to the household only to be disappointed to find doing that made her no longer the Tragic Clown. Screw that. I made her into her clowny form again. After making her miserable, I fed her to the Cowplant twice and rid the world of an evil clown. The family kept her urn and moodlet essence for posterity.
I wondered not long after if this meant the Tragic Clown was gone for good. Nope. A new one spawned. Again female, had really bad traits and was rude to my Sims. Oh, another evil clown? Well, my Sim family summoned her, so it made sense that they should take responsibility again. Rather than add her to the family, I created a "Clown Jail" with the minimum necessities. It was disappointing to find she was actually competent enough to survive despite she was miserable. So I gave in and she was added to the family and returned to her original outfit. Death by Cowplant it was and the family kept her urn and the moodlet essence.
I became curious if all Tragic Clowns spawned with bad traits/aspirations. So, my Sim summoned a new one. It was female, had really bad traits and was rude to my Sims. Wow! Maybe this was an actual feature. The Tragic Clown is actually evil as well! Either way, my Sims still had their duty. They had a small shrine hidden under the basement stairs with three urns and three essences all nicely labeled for each deceased clown.
This was pretty fun. I had a Sim family that cleansed the world of evil clowns. Well, guess what happened with the fourth summoning? A male Tragic Clown appeared with good traits and the Grilled Cheese Aspiration. Well... that puts a wrench in what my Sim family had been doing... (I came up with something else to do with the fourth Tragic Clown, but it was a lot kinder.)
I'd kind of like to play "Evil Clown Killers" again, but those were special circumstances. Oh, well.
Special mention:
Pizza Delivery service was added to the game. My Sims tried doing that. Early bugs resulted in pizza deliveries not showing up until a day or two later to not at all. I was only semi-aware of this. My Sims did fine, though, despite the long wait. The problem was that the delivery Sim arrived with an angry moodlet and she was horrible to my Sim family. If she hadn't been, all would have been fine. For her to be rude to them after arriving days late to deliver, however? I locked the front gate and the doors that entered the house.
The pizza delivery Sim remained stuck outside in the front yard until all her needs were in the red and she finally passed away. Due to guilt, however, I had one of my Sims plead Grim not to take her life. He decided not to! So, the pizza delivery Sim was brought back to life. The front gate was unlocked for her and my Sims made friends with Grim until eventually both of them left.
Do not be mean to my Sims NPCs! You'll pay for it.