Angel was a PEW rex.
Angel came with Rocket Man and Sgt. Pepper
See Rocket's page for their story.
Angel was the most quiet, gentle rat of the three. He was a complete sweetie, and accepted anyone.
Unfortunately, like Dexter before him, he developed an internal tumour and died soon after. Fortunately, he passed away in his sleep and did not seem to suffer any pain or discomfort from the lump before his passing.
Why Angel? I like angels.