Cancer remains a significant global health threat, posing a serious challenge to public health and the economy. Traditional cancer therapies, such as radiation, surgery, chemotherapy, molecular targeted therapy, immunotherapy, and antibody-drug conjugates (ADCs), have significant side effects, low specificity, and the risk of drug resistance. Therefore, there is an urgent need to develop new treatment methods to improve efficacy and reduce side effects. Antimicrobial peptides (AMPs) are natural bioactive peptides found in the innate immune systems of various organisms, and some AMPs have been proven to possess anticancer activities, known as anticancer peptides (ACPs). These peptides can specifically target cancer cells with less toxicity to normal tissues. Marine and terrestrial animals are rich sources of ACPs, which have shown promising anticancer activities. This article reviews animal-derived AMPs with anti-cancer activity, summarizes the types of tumor cells inhibited by ACPs, the mechanisms by which they exert anti-tumor effects, and discusses their clinical applications. The review highlights the structural classifications and selective recognition of AMPs to tumor cells, emphasizing the importance of anionic surfaces on tumor cell membranes. It also provides a comprehensive classification of natural ACPs from marine and terrestrial animals based on their evolutionary order. The mechanisms underlying the anti-cancer effects of AMPs, including membrane disruptive and non-membrane disruptive mechanisms, are discussed in detail. Finally, the clinical applications of ACPs are reviewed, noting the progress made in peptide anti-tumor drugs and their potential for future clinical use. In conclusion, ACPs derived from marine and terrestrial animals offer promising alternatives to traditional cancer therapies, with their unique advantages of specific targeting of cancer cells and reduced toxicity to normal tissues. The accumulation of clinical trial data in the future may further enhance the potential of ACPs as novel treatments for cancer.Cancer remains a significant global health threat, posing a serious challenge to public health and the economy. Traditional cancer therapies, such as radiation, surgery, chemotherapy, molecular targeted therapy, immunotherapy, and antibody-drug conjugates (ADCs), have significant side effects, low specificity, and the risk of drug resistance. Therefore, there is an urgent need to develop new treatment methods to improve efficacy and reduce side effects. Antimicrobial peptides (AMPs) are natural bioactive peptides found in the innate immune systems of various organisms, and some AMPs have been proven to possess anticancer activities, known as anticancer peptides (ACPs). These peptides can specifically target cancer cells with less toxicity to normal tissues. Marine and terrestrial animals are rich sources of ACPs, which have shown promising anticancer activities. This article reviews animal-derived AMPs with anti-cancer activity, summarizes the types of tumor cells inhibited by ACPs, the mechanisms by which they exert anti-tumor effects, and discusses their clinical applications. The review highlights the structural classifications and selective recognition of AMPs to tumor cells, emphasizing the importance of anionic surfaces on tumor cell membranes. It also provides a comprehensive classification of natural ACPs from marine and terrestrial animals based on their evolutionary order. The mechanisms underlying the anti-cancer effects of AMPs, including membrane disruptive and non-membrane disruptive mechanisms, are discussed in detail. Finally, the clinical applications of ACPs are reviewed, noting the progress made in peptide anti-tumor drugs and their potential for future clinical use. In conclusion, ACPs derived from marine and terrestrial animals offer promising alternatives to traditional cancer therapies, with their unique advantages of specific targeting of cancer cells and reduced toxicity to normal tissues. The accumulation of clinical trial data in the future may further enhance the potential of ACPs as novel treatments for cancer.