This cactus was given to me by a freecycler, and whereas the top looks healthy the bottom part less so, and I just hope it will be ok. She admitted it had been 'too wet'.
It looks like a mushroom-version of a barrel cactus..... about two ft tall.

Too wet? REALLY?

She might win for understatement of the year, assuming it's an Echinocactus grusonii....

Would it really grow like that if it was kept too wet? The bottom part is pretty brown, I'm giving it a 50/50 chance.

Shoot, I guess - I've never performed that particular torture on a cactus. Usually my type of torture is *no* water.... and not on cacti!

While I'm thinking of it, it will definitely croak if you change the watering practices quickly.

Plant it at the back of the border, lol!

I would poke a bit below and see how the lower part looks like. I have a cacti which got so wet during a particular winter season, and it just started to bend, upon looking below the base was sadly so rotten, so I had to chop it off..and the smell was so awful! I think I almost removed 1/3 of the plant. I had it callused and planted on a drier media. So far it has recovered.

Yes, is the brown part mushy?

Thanks for the recommendation of actually replanting the calloused top. It doesn't look mushy at this stage, but I will definitely have a good look and prod around when I take it out of its pot. Glad to know it's possible to let it re-root if the bottom part should not be viable.

As Tarev states, you should be able to cut off all t he mushy stuff, let it callous over, then plant the good part, and it will root. Cactus are incredibly tough plants. It does look like a golden barrel, but I have to tell you, those grow very well here, and I've never, ever, ever, seen one grow that long...lol!

Neither have I which is why I am puzzled ....

Garden Barrel on Steroids =)

Maybe she used Gatorade?

I'm guessing it went through a previous too wet period, possibly was reaching for more light, resulting in the part that eventually became dry looking when conditions improved and the plant grew the green top. I think I would amputate and replant the good part, being careful to let it callous and giving it a growing medium with excellent drainage. The result should be a more attractive plant.

I'm a little nervous at the amputation/callousing/regrowth process but it is indeed not now very pretty, so I will have a good look at it this weekend. If the root system is sound I will let it live the way it is, and it will eventually have other plants growing in front of it to hide its less attractive parts.

Just hack it off with a wood saw wiped down with alcohol Hetty, don't be shy!!

I don't know why I am so nervous about it, it's not like I PAID for it

Which makes it a perfect specimen for trying a new skill out on! Just make sure you're wearing welding gloves - something I learned when doing cacti "rescue" at one time.

I tend to wrap them in towels to handle them. It works pretty well.

Big thick towels are excellent for all Cactus!!!