Seems strange, but I would assume a cross maybe. Are they otherwise the same as any other Jal? Heat, taste, etc..

My husband said they taste like a nice crunchy jalapeno veggie. No heat.

It's disappointing, since it's the only one I put in the ground. The rest (from seed) are in pots. I took one more picture where you can see the clear difference.

Yes, very similar other than the sunken areas. I would let them ripen and then see how they taste. Although, it takes long time for Jalapenos to go red (ripe).

I hadn't actually let any turn red. I have cut them all off green. I'll leave some on and see how they taste red! Thank you.

Perhaps they're TAM jalapenos? If so, they were bred to be mild

This is what it said...so who knows? They certainly aren't mammoth size!

I grew one of those bonnie plants Mamoth Jal a few years ago. It had heat and I didn't really see any difference between it and any other Jal.

One of the big problem with buying starters from the big box garden centers is that kids and even adults like to switch those markers around as a joke. Or they fall out and the workers just stick them in wherever. If I buy starters, I go to the mom and pop places and have much better luck.