Volcanologist.
A scientist who studies volcanoes is called a volcanologist. These experts specialize in understanding volcanic activity, monitoring eruptions, and researching volcanic processes to help mitigate the risks associated with volcanic hazards.
A scientist who studies mollusks is called a teuthologist.
A scientist that studies viruses is called a virologist.
An Oceanographer. Marine Biologist, that sort of thing.
A scientist that studies bears would be called an ursinologist.
A scientist that studies fungi is called a mycologist.
A scientist who studies falcons is called an ornithologist, specifically focusing on the study of birds of prey.
A person who studies snowflakes is called a cryologist or a snowflake scientist.
A person who studies Political Science is called a political scientist.
That person would be called a scientist
A scientist that studies motion, forces and energy would be called a physicist.
A scientist who studies life is called a biologist. Biologists study living organisms and their interactions with each other and their environments.