I died and came back to life. My blood is not easily able to go through my body. My favorite pet is a fish. Who am I?
A shark. Sharks experience tonic immobility, also known as apparent death, where they appear to have died. Blood does not easily flow through their bodies, forcing sharks to swim continuously to circulate their blood. Lastly, sharks have pet fish called Remora (sometimes called suckerfish). They feed on parasites on the sharks and leftovers, and they use the shark as transport and protection.
A big thanks to Saravana for answering this.