Introduction: Fungi are organisms that present themselves in multicellular macroscopic and unicellular microscopic forms. They are eukaryotic, heterotrophic, reproduce asexually/sexually, cosmopolitan, achlorophyllates and are present in various climatic conditions and found in a variety of species and forms in nature. Aims: Present the emerging evolution of fungi, their underreporting, scale and parameters that show their potential as a heterotrophic organism, decomposer and pathogen. Methodology: In this review, we conducted a search emphasizing themes about fungi using the available databases and based on the scientific literature, we discussed a series of recent issues involving this wide realm and the constant controversies and expectations that guide the existence of fungi on the planet. Results: The results presented show an analysis of the action of these eukaryotic organisms and their interaction with other living beings, the constant changes in taxonomy, their pathogenic potential in plants and animals, issues related to the intrinsic resistance of some species to drugs and also the potential biotechnological for which these organisms demonstrate high plasticity. Conclusion: The expansion of fungal diseases to the fauna and flora of the planet; leads us to believe that, unless measures are taken to reinforce biosafety issues, it will be increasingly necessary to take care of the health conditions of the planet to avoid a global collapse caused by microscopic beings.