Here's the plant this one just came off of

As the plant grows, lower leaves die.

Oh thank you!!!! So it's nothing to worry about? They turn black in the middle like that though? Crazy! Thank you SOOO much!!!

It's just a natural fact, but does the rest of the plant look OK and these leaves are only coming from the bottom of the branch (while you're getting new growth)? OK, yes, nothing to worry about.

Yeah I believe that's just old leaves dying off, no need to freak out over it. Some leaves like Echeverias go yellow and then shrivel, but my Senecio haworthii's leaves also turn black and kind of squishy/shriveled when they die off too.

Keep an eye on the plant, and as long as it's not losing leaves unusually fast and new leaves look healthy then it should be fine.