A helminth, but one not to be worn on the head. Toxocara canis from dogs; Toxocara cati from cats.
Stepping in cat poo or dog poo and feeling it squish between your toes; I hate dogs and cats. Eating food covered with the same
And eating raw ostrich liver (PubMed).
Visceral larva migrans: the worm taking a walk through your peritoneum.