Professor Larkspur is a scientist located in Silverport Town in the Tandor region. His work specializes in creating technology that can more easily capture and control Pokemon.
From the notes on his lab's software, he also led "Project 092" along with "Dr. XXXXX", but he ditched the project when he grew suspicious of Dr. XXXXX's intentions. This led to him destroying Power Plant Epsilon to get rid of Project 092.
His name comes from "Larkspur", a type of flower, following the main series' trend of naming professors after plants, albeit also breaking it by not naming him after a tree. This flower is extremely toxic to people and animals alike, which foreshadows Larkspur's villainy.