Milhouse this is the guide they’re talking about: KD's Bonus Potions and Entrance Speed guide
Monsters get a turn in 35 + [(100 - speed stat) * 0.8] seconds.
Say a monster is 99% speed then it gets a turn in 35 + 0.8 = 35.8 seconds. Every 1% of speed lower than that means it will take 0.8 seconds more to get its first turn when it comes onto the field.
Pupupa here will get a turn in 35 + (100-26) * 0.8 = 35 + 59.2 = 94.2 seconds.
Potion bonus will reduce the overall time it takes by a percentage.