The Tax Collector

In "Our Ancestors the Humans", the aliens encounter a tax collector who threatens to take the house's furniture, saying that they owe 23 years of back taxes. They use Etno's time machine to teleport to certain time periods, only for the tax collector to follow them every time. The episode ends with the tax collectors from all four depicted time periods showing up at the aliens' door, much to their chagrin.

Example of:
Failure Is the Only Option