Harrison Wells

Harrison Wells is the adopted identity of Eobard Thawne, the Reverse Flash, who is the primary antagonist of the first two episodes of "The Flash".

History
Harrison Wells is the owner of STAR Labs who owned the company to begin with. However, when Eobard Thawne arrived in the 21st century, he killed Harrison and took his place using a DNA changer to appear as the deceased Wells

Pilot:

In the first episode, Harrison is trying to encourage Barry to run, but he refuses even after he says "Run, Barry, run!". After Ronnie Raymond is killed by Reverse Flash, Harrison tells Barry to come to STAR Labs as soon as possible. While Reverse Flash escapes, it is later revealed that Harrison Wells is the Reverse Flash, which Barry discovers almost immediately. Fast Enough?:

Barry asks Harrison why he killed his mother, but he refuses to tell unless Barry catches him. After a long chase, Harrison bamboozles him by saying Grodd is behind him, giving him the opportunity to run away.

Speed Weed:

Barry, high on Speed Weed, confronts Harrison, as Reverse Flash, outside the police station. He is eventually knocked out as Barry throws blue speed force lightning at him. Jay Garrick, actually Zoom, then places a speed dampener on him and drains his speed.

How To Mess Up A Timeline 101:

Harrison wakes up and asks Barry what happened. Barry, now without speed, explains that Zoom took their speed. Harrison claims that Zoom is his rival.

After travelling back in time to the events of the episode Speed Weed, Barry decides he needs to team up with Harrison in order to beat Zoom and keep their speed.

The Bamboozler

In the Season 2 premier, Harrison chastises Barry for using time travel as a means to get help. He then leaves.

Behind the scenes
If there's anything you'd like to say that's not derived from episodes, but maybe comes from interviews that actors or crew gave, use this section.