The die was filled with grease and/or debris and caused this. It’s a mint error but they are very common and bring no extra money. Nice to find in change.
when it's said "brings no extra money" what is meant is if you sell it on ebay it would probably land you $2-$5 in circulated condition, but a dealer likely wouldn't even want it beyond 25 cents, (no meat on the bone for him) and it wouldn't be worth the cost of grading it (would cost many times more than it's worth to get it graded). But, it's worth a buck or two if sold to an end user that wants it. Not all greasers are worth even that, but this particular one is kind of popular. it has a bit of value over face value, it's a good find. Many errors are 50 cents to $5.00 if sold to an end user directly, it's not gonna make you rich, but it has value more than face.
Yup. I don't even keep the ones with just the "T" missing. I find plenty of those in my boxes I only keep them if more letters are missing.
Because of the results with the T missing, this is a fun find, and I would certainly keep it. Nice job.