Mad Scientist

Mad scientist (also mad doctor or mad professor) is a caricature of a scientist who is described as "mad" or "insane" owing to a combination of unusual or unsettling personality traits and the unabashedly ambitious, taboo and/or hubristic nature of their experiments. As a motif in fiction, the mad scientist may be villainous (evil genius) or antagonistic, benign or neutral; may be insane, eccentric, or clumsy; and often works with fictional technology or fails to recognize or value common human objections to attempting to play God. Some may have benevolent or good-spirited intentions, even if their actions are dangerous or questionable, which can make them accidental villains.

The prototypical fictional mad scientist was Victor Frankenstein, creator of his eponymous monster, who made his first appearance in 1818, in the novel Frankenstein, or the Modern Prometheus by Mary Shelley. Though Frankenstein is a sympathetic character, the critical element of conducting experiments that cross "boundaries that ought not to be crossed", heedless of the consequences, is present in Shelley's novel. Frankenstein was trained as both alchemist and modern scientist which makes him the bridge between two eras of an evolving archetype. The book is said to be a precursor of a new genre, science fiction, although as an example of gothic horror it is connected with other antecedents as well.

1896 saw the publication of H. G. Wells' The Island of Doctor Moreau, in which the titular doctor—a controversial vivisectionist—has isolated himself entirely from civilisation in order to continue his experiments in surgically reshaping animals into humanoid forms, heedless of the suffering he causes.

...
Wikipedia