I don't know what it is, Alex, but it's not in very good shape. Are you looking for help with it?

Burro's tail

@Socks yes please! I was given it as a gift from a friend who was looking after it for me (not very well it seems) about a week ago!

The plant is almost dead, sorry. Don't blame your friend; blame the pot and the soil. You can save it and learn something too: You must clip it off just above that hole near the soil. Then remove about 3 of the lower leaves, allow the stem to dry several days, then gently plant the dry stem into a fast draining mix (like cactus/succulent mix from a nursery) in a small pot. Do not water until you see growth on the top. It will be OK. Also, carefully with a knife or scissors trim whatever is dead on the top of the plant.

I notice a cactus in that pot as well. It won't last long in there either. It's potted way too low, pot too big and wrong soil will hold too much water for a cactus. Use that same cactus mix and repot the cactus in a smaller pot, and pot it much higher than it is now. You can water the cactus in a week or so. Both plants need lots of light but bright shade or a bright location is good while they are recovering.

As for pots, they are fairly inexpensive at nurseries, Home Depot, etc. Clay or plastic is ok, but you'll have to be more careful about overwatering if in a plastic pot. Cactuses and succulents don't like oversized pots because they have small root systems, and if there is too much soil, it just holds water and the plant can rot. They never grow into a big pot like kids grow into clothes too big! Remember these plants store water in their stems and leaves and cannot tolerate overwatering. Also, the pots absolutely must have holes in the bottom.

Sounds like a lot to save two little plants, but it can be fun and rewarding to rehabilitate plants by giving them the perfect growing conditions.