No vertebrate (fish, mammal, bird, reptile, or amphibian) has ever had an odd number of limbs. Despite this "forbidden phenotype," some animals seem to use other body parts as a third or fifth "limb" to move from one place to another.
source https://www.lifetechnology.com/blogs/life-technology-science-news/study-finds-parrots-use-their-heads-as-a-third-limb
