The reptile known for regrowing its teeth throughout its lifetime is the crocodile. Crocodiles have a remarkable ability to continuously replace their teeth, allowing them to maintain functional dentition over the course of their lives. This process is essential for their survival, as their teeth can wear down or break during activities such as catching prey or engaging in territorial disputes. The new teeth typically grow in the sockets of the old ones, ensuring that the crocodile maintains its ability to hunt and consume prey efficiently.