Uroboros is the symbol of a system that consumes itself, either literally or symbolically. There are many kinds of feedback processes you could liken to a serpent eating its own tail. The compost from one generation of plants nourishes the next, for example, so the new generation is partly consuming the decay of the last generation, the “tail” of the cycle of growth and decay.
You definitely would not call plants growing in their own compost “self-cannibalistic”. Consuming ones’ own living parts, however, is quite an apt description of what happens at the natural limits of a growth system that ends its growth only because it exhausts its free resources. In economies the more competitive parts may then find nothing more interesting left to consume other than their own system’s weaker or less familiar living parts… (discussion contued at end)