'Octopuses can sometimes suffer from autophagy, or self-cannibalism. That is what is described as "eating its own arms." This is caused by stress.' (source: tonmo . com)
'They're semelparous, which means they reproduce just once before they die. With female octopuses, once she's laid her eggs, that's it. In fact, the mother even stops feeding - she'll stay and watch over her eggs until they hatch, slowly starving to death. In captivity, towards the end, sometimes she'll tear off her own skin, and eat the tips of her own tentacles.' (source: sciencealert . com)
So uh, yeah, apparently they can.
'They're semelparous, which means they reproduce just once before they die. With female octopuses, once she's laid her eggs, that's it. In fact, the mother even stops feeding - she'll stay and watch over her eggs until they hatch, slowly starving to death. In captivity, towards the end, sometimes she'll tear off her own skin, and eat the tips of her own tentacles.' (source: sciencealert . com)
So uh, yeah, apparently they can.