This scenario sounds like it might be considered a “gift” from someone and subject to the gift tax guidelines federally. The giver is usually the one who is required to file and pay taxes for a gift but only if the value exceeds 15K USD per calendar year. If the value of the gift was more than 15K the giver would have to file and possibly pay any applicable taxes but only if they used up their lifetime exclusion. On top of the $15,000 annual exclusion, you get an $11.7 million lifetime exclusion. So the giver shouldn’t have any tax liability unless the total of the gifts exceeds $11.7 mil in their lifetime.
For the receiver of a gift, if the asset then produces an income after receipt of the gift (like collecting dividends, rewards or interest from the gift), that income would then likely be taxable under current tax law. Also, if the receiver sold said coin for fiat, they would likely be liable for income taxes from that sale. But the receiver wouldn’t be liable for taxes just for receiving the gift AFAIK. I think the creator of said coin would have more potential tax worries than the receivers in this scenario.