Literally, a brainworm

I guess this story will further cement Australia's reputation for all things dangerous: 

Woman complained of forgetfulness and depression before doctors pulled out an 8cm roundworm normally found in pythons

It's kind of interesting that her earlier symptoms were to do with digestion, though:

It was a fairly regular day on the ward for Canberra hospital infectious diseases physician Dr Sanjaya Senanayake, until a neurosurgeon colleague called him and said: “Oh my god, you wouldn’t believe what I just found in this lady’s brain – and it’s alive and wriggling.”

The neurosurgeon, Dr Hari Priya Bandi, had pulled an 8cm-long parasitic roundworm from her patient, prompting her to call on Senanayake and other hospital colleagues for advice about what to do next.

The patient, a 64-year-old woman from south-eastern New South Wales, was first admitted to her local hospital in late January 2021 after suffering three weeks of abdominal pain and diarrhoea, followed by a constant dry cough, fever and night sweats.

By 2022, her symptoms also included forgetfulness and depression, prompting a referral to Canberra hospital. An MRI scan of her brain revealed abnormalities requiring surgery.