flubber

[spook]

i got a triple flubber (121) and it has a 2% respawn buff. what does that mean?

[Elenoe]

monters in adventure (and ITOPOD) spawn faster. Which means more kills (and later in ITOPOD more PP, XP, poop and faster quests)

Base respawn time is 4s (+0.8-1.0s to kill them). It will go significantly lower as you progress. Base 2% can go up to 8% for maxed flubber. And it might be worth keeping it (Although I've never used it, there are better items.)

Respawn items are worth using when you start spending most of time in ITOPOD which is by the time you kill UUG. And he drops the one of the best items in the game with 16% respawn which you should use pretty much forever.

[Fel]

Respawn is the time between the moment you kill an enemy and when a new one appears.
It is 4 seconds as the base value.

It needs to be noted that the time to kill an enemy is respawn + number of hits * time between attacks.
The time between attacks is 1 second at the start, levelling item 93 to 100 will make it go down to 0.8 second.
You can see your current value for respawn in the stat breakdown (you can access it either from "info 'n stuff" or from the inventory).

This means that even in places where you 1-hit enemies you need to add 0.8 or 1 second to the respawn because it takes that long for the idle attack to trigger when an enemy respawns, and that isn't impacted by the respawn bonus.