Starfish can regenerate their arms. If a starfish loses an arm, it can grow back a new one, including the various structures like nerves, muscles, and even internal organs. Some species can even regenerate their entire body from a single arm.
Male deer grow and shed their antlers every year. The process of antler regeneration is unique to deer. Additionally, it can also regenerate other tissues, such as the liver. In cases of liver damage, the mammal can regrow the lost tissue.
Some species of spiders can regenerate lost legs. Although the regenerated leg may not be a replica of the original, it allows the spider to regain mobility.
Certain species of jellyfish can revert back to an earlier stage of their life cycle and then regrow into mature individuals. This process is called transdifferentiation, and it allows them to regenerate their entire body.
The axolotl is a type of salamander that exhibits exceptional regenerative abilities. It can regenerate not only limbs but also the spinal cord, heart, and other organs. This makes it one of the most proficient regenerators among vertebrates.