Final answer:
Certain animals, characterized as scavengers or decomposers, feed on the facial tissues of dead animals. These include a variety of species, with specialized anatomical adaptations for consuming such tissues. Examples are insects, birds, and mammalian scavengers like hyenas and vultures.
Step-by-step explanation:
The animal which mainly consumes facial tissue such as lips, eyeballs, and noses would typically be a scavenger or decomposer. These are creatures that feed on the soft tissues of dead animals, often after the remains are left by predators. Numerous organisms play this role in the ecosystem, including some insects, birds, and mammalian scavengers like hyenas and vultures. These animals have evolved to take advantage of this food source and efficiently extract nutrients from the decaying organic matter.
Looking at the wide variety of mouthparts among animals, it's clear that different species have adapted to consume different types of food. For example, herbivores have grinding molars, carnivores have sharp cutting teeth, and scavengers may have beaks or teeth designed to tear soft tissue. This diversity in anatomical structures illustrates the specialization of species within their respective niches in the food web.
Additionally, the domestic and international trades of animal parts for food, as seen with turtles, snakes, and various bird species in Asian markets, indicate a human demand for these resources. However, it's important to note that this does not relate directly to the consumption of facial tissue, as posed in the original question.