Doobie is a minor antagonist featured in Phantom Blood. He is a musclebound masked zombie that Dio Brando sics on Poco's Sister after she refuses to serve him. Doobie grabs the girl and rips her dress in an attempt to assault her, but his plan is quickly ruined by an anvil thrown by Jonathan Joestar.

(Source: JoJo's Bizarre Encyclopedia)

Beginning its tale in 19th century England, young aristocrat Jonathan Joestar finds himself locked in bitter rivalry with Dio Brando, a low-born boy who Jonathan's father took under his wing after the death of Dio's father. Discontent with his station in life, Dio's fathomless lust to reign over all eventually leads him to seek the supernatural powers of an ancient Aztec stone mask in the Joestar's possession—an artifact that will forever change the destiny of Dio and Jonathan for generations to come. 
 
Fifty years later, in 1938 New York City, Jonathan's grandson Joseph Joestar must take up his grandfather's mission and master the abilities necessary to destroy the stone mask and its immensely powerful creators who threaten humanity's very existence, the Pillar Men. 
(Source: Anime News Network)

He is known for playing tough or grouchy men in dubbed anime and video games. His career includes Hotohori in Fushigi Yūgi and Jin in Samurai Champloo. He also played numerous cameos and minor characters in Rurouni Kenshin, in addition to the major character of Hajime Saito. He also does Don Patch in Bobobo-bo Bo-bobo as well as Gabumon and other voices in Digimon.  According to Anime News Network, Thornton has the most credits of any male voice actor and he is second in total voice actor credits only next to Wendee Lee. He has been in nearly two hundred voice-over productions for Japanese animation.  Thornton is also well-known for having played many different minor voice roles throughout the Power Rangers franchise (and similar series such as VR Troopers and Masked Rider).  Thornton has also had experience with ADR direction. Currently, he is co-directing the ADR for the popular anime series Bleach alongside Wendee Lee.

Young Jonathan Joestar’s life is forever changed when he meets his new adopted brother, Dio. For some reason, Dio has a smoldering grudge against him and derives pleasure from seeing him suffer. But every man has his limits, as Dio finds out. This is the beginning of a long and hateful relationship!
 
(Source: Viz Media)