A friend just gifted me this plant. It's got thin, papery, spiky leaves. What is it?
I disagree with aloe, the paper-thin leaves and the deep well in the center of the leaf rosette indicate a member of the bromeliaceae family.
I can't give a precise id (and am no expert on bromeliads) but this should guide you in the right direction.
This is not an Aloe. Most Aloes retain water in the leaves and for that, they have a fleshy construction.
The thin leaves and spikes potentially make it a member of the Agave genera or the Bromeliaceae. Agave leaves can be really thin and those well spaced spikes are very characteristic. The species is hard to tell with these photos and no other information, but look for Agave bracteosa or many of its variegated cultivars.
If it is Bromeliaceae, it will almost always flower from the middle in distinct leaf like rosettes that then will help you identify what it is. Agave and Aloes tend to flower with a long stalk, also usually from the center that then terminates in florets.
You can try to get more info from your friend on where they bought it, or what they propagated it off of for a better call. Or, wait till it flowers and then that will be a great giveaway. I subjectively think it is an Agave from the spaced spikes on the leaf edges.
This is not part of your question but, soil looks a bit too wet. Allow to dry between watering.
This is most likely Billbergia nutans or "Queen's Tears", a very common houseplant. Also known as "Friendship Plant" since it readily forms baby offshoots which are easily shared. A flower would help provide a positive ID, but I have grown many of these in the past and I'm quite certain.
Care: House Plants Expert
I think this is a Sacred Onion aka Pregnant Onion (Albuca bracteata/Ornithogalum longebracteatum). If it has a large bulb under the soil. They like to be planted with the bulb on top of the soil. Eventually you will see a "bump" on the bulb and soon you will have a baby onion that you can share. Sports at times to come from underneath and you could divide that way.