What animals never had to evolve?

This is a tricky question! It's important to remember that all living things evolve, even if it's at a very slow rate. Evolution is a continuous process, and even seemingly unchanged species have undergone small adaptations over time.

That being said, there are some groups of animals that appear to have remained relatively unchanged for long periods:

* Extremophiles: These are organisms that thrive in extreme environments like hot springs, deep sea vents, or extremely salty environments. Due to the lack of competition and stable environments, they may have experienced less pressure to evolve.

* Tardigrades: These tiny, water-dwelling creatures are known for their incredible resilience and ability to survive in extreme conditions. While they have evolved to withstand these challenges, their basic body plan has remained relatively unchanged for millions of years.

* Coelacanths: These "living fossils" have been around for over 400 million years, and their basic body shape has remained largely the same. However, they have still undergone genetic changes and adaptations over time.

It's crucial to note that even though these organisms may appear "unchanged," they have still evolved over time. Evolution is a constant process, and even subtle adaptations can be significant for the survival of a species.

So, while there are animals that have maintained their basic form for long periods, it's inaccurate to say they never had to evolve. Evolution is a universal process for all life on Earth.