Basically name an absurd way, even if it is impossible or over the top exagerated. Name a very silly way to score a pentakill.

Example:
Allied Katarina about to score the pentakill, but Soraka flashes over a wall and kills all 5 enemies at once with a single starcall.

A blitzcrank player's mouse is broken, while he tries to fix it low health enemies run into him and his ult's passive kills them all.

Zilean drops bombs on enemies and the gets bursted down. his team runs away from the fight but enemies are low. they camp his body as he ulted himself. the bombs go off, he revives and drops more bombs on enemies.

i actually got a triple like this

Enemy team steals Baron and grabs a quadra. Left low and not pushing, They all recall in the same bush. AP Ez ults the bush....

Shen taunts the whole team, penta.

you have an afk ranged champ on your team sitting in fountain and the entire enemy team fountain dives while he gets auto attacks in while the fountain kills them all

The enemy Morde ults and kills your AD carry. Afterwards, you see in the chat "jajajaja"

The enemy chases an AP Teemo through his minefield

Heimerdinger flashes in from over the wall at the end of the fight, ults and then shoots 5 rockets and all 5 hit to get the penta kill! (Actually I got a quadra like this once after the rest of my team was dead... the other team raged so hard... I was pretty amazed myself)