Dr. Zin is possibly the most fickle villain ever, punishing his minions with horrible deaths at the slightest provocation. We get three examples of this with the control room technicians aboard his cloaked asteroid base (no villain is complete without one!).
425 is the current leader. What happened to numbers 1 through 424 is never said... but given Zin's track record here it's easy to guess. First a little info on the plot.
From said asteroid base, Zin has launched a satellite capable of changing the weather, so as to leave Earth crippled for invasion by his mutant cyborg bugs. Sensing that Dr. Benton Quest may come into space to investigate the satellite, Zin decides to nip this little problem in the bud. To this end, 425 dispatches three "Formicoids" - mutated cybernetic ants - to Earth to kill the Quests.
The insects fail miserably and are killed by Dr. Quest's brat kid Jonny and his friends. Not long after, Zin and his staff watch on a giant viewscreen as Dr. Quest's shuttle lifts off for outer space - 425 most worried of all.
Realizing how thoroughly screwed he is, he reports simply, "Uh, I am sorry, sir. I... failed." Those last two words essentially seal his fate. If you're a henchman for a power-mad villain, never ever say those words.
Zin is less than pleased and rants about incompetence.
The technician pleads with his employer for a second chance: "Don't worry, Dr. Zin, I'll stop Quest! Just wait!"
"Wait for what, 425?" roars Zin. "More incompetence?" He pushes a button, and three "Hymenoptoids" (huge, mutant sandflies) fly in and surround the terrified 425. Two of them seize 425 by the arms, and with a scream of "Nooooo!" the luckless man is flown away to die a clean offscreen death. Can't go disturbing the kiddies too much.