Which animal's teeth grow continuously throughout their life?

I saw a swimming beaver up close and personal this year under a wooden walkway over the Neuse River in New Bern, NC. I had no idea they were so long and big!

I seen this on YouTube.

Same with hamsters.

An Elephant tusks continues to grow though out it's life

Dorothy , they don't replace they continuously grow. I think.

if thier teeth didn't get replaced they would not continue to be able to make dams.