Nerd brigade fanfare plays
The notable resiliancy of fluffies probably won’t give them an advantage when it comes to electricity or radiation.
Let’s start with electricity. Electricity is defined as the motion of an electrical charge through some conductor, and has two primary values associated with it. Voltage, which is the potential difference between two points, and Current, measured in Amperes, which is the rate of flow. An ampere of current is equal to one Coulomb of charge per second past an arbitrary point in a conductor.
Together, these give you Watts, where 1 Watt = 1 Volt of charge, moving at 1 Ampere. Handily enough, 1 Watt is also 1 joule per second, which gets handy-dandy when you’re doing power calculations.
Now, it’s a common misconception where people say ‘hurr durr it’s the volts that jolts and the mils that kills’. Or, it isn’t the voltage that is dangerous, but current.
This is a dangerous misconception. Electricity is hazardous based on how much energy it is dumping in you, and where it is flowing. If you put your finger between two wires going into a plug, you aren’t going to die. It’ll suck, but you’ll be fine for the most part. Voltage is like water pressure, current is like flow volume. It doesn’t take much water to make a high pressure cutting jet, and you can drown in a still lake.
Let’s assume with a fluffy you have the best-case scenario where they have their hind legs in a puddle of water and their forelegs are trying to speedbag a lightbulb. Current always, always, always takes the path of least resistance, and wants to get to the nearest lower potential. So, it goes through the fluffy, and passes through the fluffy’s heart.
Yay it’s dead. Unless you have a GFCI on that lightbulb socket but that’s engineering so let’s ignore it for now. In humans, it takes as little as 30 milliamperes of AC current to make your heart have a derp and take a nap. Given fluffies seem to be engineered to be tough little goobers I’d say you could probably argue that 15-20 would be their lethal threshold.
Now, that’s for AC, at 60 hertz. I am not going to go into an explanation of AC beyond ‘DC means the current always flows in one direction, AC means it swaps periodically, and on the US grid that’s 60 times per second.’
DC requires a bit more current to cause heart stoppage, around 400 milliamperes. However, what is more significant with both DC and AC current is heat. Anything that isn’t a superconductor has an inherent resistance to it. Even really good conducting metals like gold and copper resist to some degree, and this causes power to be lost in the system, usually as heat. The more resistance, the more heat is lost.
This is how a filament lightbulb would function, the filament itself is just a high-value resistor that’s built to resist current so much the heat makes it glow.
So let’s say a fluffy was hooked up to a high wattage lab power supply. At the contact points, it would develop burns, and these burns get worse as you go down in layers. Fluff is a decent insulator, but once you get into the wet parts of a body, the resistance goes down, which means the current goes up, which means that more power is dumped. Nerve damage would also be extensive, and there is a very real chance that meat somewhere between the two contact points would start getting cooked.
Interestingly enough there is this thing called the ‘skin effect’, where if you have a high frequency AC current, in the tens of kilohertz at minimum, the AC current would want to pass closer and closer to the surface of an object. This is how Tesla was able to stand literally inside a rainstorm of electricity and not be harmed.
On radiation, it’s a bit simpler. They’re made of roughly the same stuff as humans, so alpha and beta probably wouldn’t do shit to them unless they ate the radiation source. Gamma radiation dosage has lethality based on body mass, so tiny poop gremlin means proportionally lower lethal dose.
TL:DR - Probably around the same amount of electricity to kill a 15kg dog. Radiation is by size so just lower the lethal dose to their mass.
