Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that most animals derive their nutrition by . Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that most animals derive their nutrition by . consuming living, rather than dead, prey preying on animals using enzymes to digest their food ingesting materials

Both animals and fungi have a heterotrophic mode of nutrition.
This means that they are incapable of producing their own food and energy and depend on other organisms for their food and energy.
Fungi derive their nutrition in three ways:

They derive organic nutrients in soluble form from dead and decaying organic matter. Here they act as Saprotrophs.
They survive within their living hosts and derive soluble organic nutrients directly from the host. Here they act as Parasites.
They obtain nutrition by undergoing mutualistic relationship with other organism such that both the organisms benefit from the interaction.

In all the cases, the fungi derive nutrition in the form of simple soluble organic components from the host (dead or living).
They usually secrete exo-zymes outside their body in the surrounding environment those help in digesting the complex organic components of the host into simple organic molecules.
These simple organic substances are then taken up by the fungi.
However, animals derive nutrition by ingesting the food components in the complex organic form.
These components are broken down into simple organic components as the food is passed through the alimentary canal of the animal, by mechanical process or by the action of enzymes secreted in the alimentary canal within the body of the animal.
These simple organic components are then absorbed by the cells of the animal body.