There is no such thing as an "audiobook in the public domain", unless you recorded it yourself from a public domain literary source. If you found a recording of a Public Domain media source done by a third party, it is under the copyright of either the recordist, or the distribution site. Public Domain media is among the sources declared non-monetizable by YouTube; and if you have an audio recording with a static image backing it, this will automatically be found non-monetizable by the channel review teams.
A Monitor lizard "tearing up a rabbit", is doing it because he is hungry. Do you deny meat-eating predators the right to hunt their lawful prey in order to eat? I've seen people try to put cats and dogs on a vegetarian diet. The result in every case, has been an intervention by the Anti-Cruelty Societies or Societies For Prevention of Cruelty To Animals when the animals either refused such food to the point of starvation, or ate it because there was nothing else available; and ended up suffering from malnutrition.