Sizzzz

“Aren’t you supposed to be dead?”
“Hm? Oh, well yeah, but I can’t just leave. Some of my companions don’t even know how to make sticks yet.”

Origin
Sizzzz was once a nether lava-dweller. Her markings being that of an inverted mandarinfish. However, she had always hated how vast, but enclosed, the nether felt and moved to the overworld years ago. When she goes back on rare occasions, she often forgets she’s no longer fire resistant and jumps into lava haphazardly.

Deaths
Being a mentor is dangerous. Whenever she tries to pass on wisdom to her companions, she inevitably gets distracted in perilous situations and dies.
Once, she tried to help one of her new students (an enderman-like being) navigate the nether. After a grueling trek across lava lakes and mountains, they found themselves at the base of a basalt delta. It felt like they had been trapped in the nether wastes for ages, so Sizzzz was excited to climb to the top and see what was over the horizon. However, as she turned around to talk to her companion, she mined through a stray block and lava poured down around her. Her student was able to escape the flow, so her final words to them were "I believe in you."
Another time, Sizzzz was traveling the overworld looking for desert temples and villages. Her and a different, undead, companion had already faced off against pillager raids and hostile zombie attacks with limited success. But when they tried to make their way home by horseback, Sizzzz let her guard down. As she tried to explain the intricacies of their world, a hoard of mobs overtook her.

Internet Crashes
She is too powerful. Outside forces must keep her at bay. They already erased her once. Alex the human? Was it? This current form seems to be a little more robust.