No, as a matter of fact, they aren't. They are poisonous fruits of a potato plant.
Potatoes are members of the plant family solanaceae, which includes tomatoes, peppers, eggplant, and tomatillos. Those are the friendly solanaceae, but you have to remember that the family also includes deadly nightshade and datura, which are poisonous.
I'd never seen this on a potato plant, but an internet search suggests that potatoes will set fruit like this when growing conditions include long daylight hours and a cool temperature.
Well, that would certainly be here, in 2023, when we were still building a fire in the woodstove in May (ridiculous) when normally we'd have our last wood fire in February.
They say that if you let the fruit mature, and use their seeds to plant potatoes, that you can come up with some interesting new varieties. Maybe one day we'll fence off a fruit-producing potato and try that.
But for now, we trimmed the fruit off and put it in the city composting cans -- we have toddlers in the neighborhood who know that we grow sweet little Sun Gold tomatoes and are not above making expeditions to our front yard to view the goldfish pond and sample the veggies and fruits.