The Ecto Leeches are ghosts who feed on electrical energy. As a result, they are attracted to large power sources. They then confer the absorbed energy to their queen, Lilith. In November 1997, they caused a power blackout and attacked two ConEd employees named Stan and Charlie. ConEd called in the Extreme Ghostbusters but after three hours and three miles of raw sewage, Egon Spengler, Eduardo Rivera, and Kylie Griffin returned to the Firehouse empty handed. They received a second call sighting the Ecto Leeches but where nearly carried away by a wave of water accidentally released when Kylie shot a wall. During the third encounter, at a power plant, they managed to trap two leeches.
Lilith released the trapped leeches and trapped Slimer. She returned to her lair underneath Penn Station and used her leeches' energy to form a Bio Containment Vortex. Lilith planned to trap humans in it and use their life force to provide her with limitless power. Slimer was released and he slimed two Ecto Leeches then trapped Lilith.
According to Egon, Ecto Leeches have incredible energy absorbing capabilities.
- Lilith (1997). Extreme Ghostbusters- A Temporary Insanity (1997) (DVD ts. 09:37-09:41). Sony Pictures Home Entertainment. Lilith says: "Now how about bagging a couple of Ecto Leeches for Lilith?"
- Eduardo Rivera (1997). Extreme Ghostbusters- A Temporary Insanity (1997) (DVD ts. 02:59-03:03). Sony Pictures Home Entertainment. Eduardo says: "Three hours crawling in the sewers looking for Electric Leeches and what did we get?!"
- Egon Spengler (1997). Extreme Ghostbusters- A Temporary Insanity (1997) (DVD ts. 09:02-09:08). Sony Pictures Home Entertainment. Egon says: "These ecto entities possess incredible energy absorbing capabilities. They are clearly attracted to major power sources.."