Can someone who doesn't work file taxes?

What do you mean? Anyone can file taxes. Yes, people who don't have income can file taxes. If they don't have income then it would probably show 0 in the income column and probably 0 in withheld taxes, so it's not very interesting. People without income may not be required to file, but it never hurts to file. There's no fraud unless you claim something that is not true (e.g. you say you have income when you don't).

People don't "file taxes" or "claim taxes". They file a tax return. A tax return reports their income and possible deductions and credits to calculate how much they may owe in taxes. That amount is compared to how much they have paid towards their tax liability and it is then determined whether they owe or are owed money,

Because of certain tax credits available. It is possible that a person without a job may be entitled to money. Nor does not having a job mean they don't have income.

Can you explain why you are asking? Maybe we can advise further.

Yes; undergraduate college students who have zero income, but are considered independent from their parents can file to claim the $1,000 refundable credit offered under the American Opportunity Credit.