Animals take many shapes and varieties and are available a great range of sizes, from microscopic to the 30 m long blue whale! Whether you measure when it comes to weight, top or size, there is no denying some animals are huge compared to others in their class. MDPI operates Preprints, a preprint server to which submitted papers may be uploaded instantly after completing journal submission. Note that Preprints operates independently of the journal and posting a preprint does not affect the peer evaluate process. Check the Preprints instructions for authors for further info.