This practical chapter focuses on the comparative classification of animal eggs and their cleavage patterns, offering foundational insights into early embryonic development. The process of cleavage, rapid mitotic divisions following fertilization, is profoundly influenced by the quantity, distribution, and orientation of yolk within the egg. Eggs are categorized based on yolk concentration (alecithal, microlecithal, mesolecithal, macrolecithal) and distribution (isolecithal, telolecithal, centrolecithal, discoidal), each affecting cleavage symmetry and completeness. Cleavage patterns are broadly divided into holoblastic (complete: equal or unequal) and meroblastic (incomplete: discoidal or superficial), determined by the physical limitations imposed by yolk density. The orientation of cleavage planes, meridional, vertical, equatorial, latitudinal, and oblique, influences embryonic polarity and axis formation. Eggs are further classified based on external coverings as cleidoic (shelled) or non-cleidoic (unshelled), reflecting adaptations to environmental conditions. Students are introduced to classical embryological concepts such as mosaic (determinate) and regulative (indeterminate) development, essential to understanding cell fate and embryonic plasticity. Through examination of diagrams and photomicrographs, students will be able to identify egg types and their associated cleavage patterns. This practical chapter/exercise aims to build an understanding of how egg structure governs embryogenesis and contributes to evolutionary diversity in reproductive strategies. Such knowledge is central to developmental biology and underpins further studies in embryology, evolution, and cellular differentiation.