Actor Jeff Conaway, was best known for his roles in the movie Grease and the television series Taxi and Babylon 5. On B5, Conaway portrayed security officer Zack Allan, his character was eventually promoted to Security Chief, and he maintained that position through the end of the series fifth and final season. Conaway also reprised his B5 role in the telefilms Babylon 5: The River of Souls, Babylon 5: Thirdspace and Babylon 5: A Call to Arms.
Conaway struggled with various substance addictions throughout most of his career and it was this predilection that resulted in his firing from Taxi back in 1982. A serious back injury on the set of Grease plagued him for many years, and a combination of both situations landed him on two crummy reality shows, Celebrity Fit Club and Celebrity Rehab with Dr. Drew, where his wild manifestations were truly evident.