Can't help but think how merformer Prowl and a human would meet. Human would be doing laundry in the river (like how they did before, ya know) and is really serious and diligent in doing their task. Later on for some reason Prowl springs his head up from the deep side of the river, and when human sees him. They just stare at each other. Like. Okay. Howdy creature of the deep.
Imagine the human losing a scarf or something and having it be carried down by the river, only for it to reappear moments later, carried by a large, river dwelling merformer. The human is speechless as this creature of legend (that they had been previously unaware actually existed before this moment) stares down at them with an unreadable expression. Finally the creature speaks as he hands them back their scarf.
“Please keep better track of you clothes. I don’t want to have to keep fishing them out of the river.”
Little does the human know that this is actually Prowl’s version of flirting.