Corpse weight is constant?

Why do all zombies seem to leave a corpse that weighs exactly 81.5kg?

Because it was coded that way.

They don’t. Not all of them.

Snotgobbler, Boomer, Bloated, Gasoline & Smoker Zombies disintegrate with no corpse left behind.
A Zombeaver comes in at 20.00 kg.
Anklebiter, Creepy Crawler, Shriekling & Zombie Childs, as well as most - if not all - Zombie Dog variants leave a corpse with a weight of 40.75 kg.
Brainless Zombies come in portions of 78.20 kg corpses (because of missing body parts).
Zombear & Antlered Horror corpses is 120.00 kg.
Zombie Horse corpse is only slightly heavier with 125.00 kg.
Zombie Hulks have a body weight of 200.00 kg.
Zombie Cows leave you with 680.00 kg of dead meat.
And then there’s the Zombull corpse, which comes in at 750.00 kg.

…Just to name a few…

Other than that, it makes the program more lightweight to run (ha, that pun wasn’t intended) if it doesn’t have to add random weights (and remember them all) for all the random Zombies.
It goes into the same category as “Why do all zombies look the same?” - that one’s depending on the tileset, of course.

well its more accurate to say that the exploding zombies… explode. and zom-animals are mostly equivalent to their non-zombie counterparts

I’m not sure how it’s “more accurate” to say “Zombies explode” insted of “… disintegrate”, it ends up at the same conclusion: No corpse left behind, nothing that you could weigh.

Yes… and that makes it different to the weight of other Zombies.

Sort of the weight of some zom-animals are smaller than their living counterparts (namely antlered horror’s) and some living animals don’t have the correct weight as they would have in real life (looking at moose again).

i did say ‘mostly’, and calculating the exact weight of a moose over its value as a meat-product is kinda tricky.

fat zombie is also 81.5kg.

more lightweight to run (ha, that pun wasn’t intended) if it doesn’t have to add random weights (and remember them all) for all the random Zombies.

/me looks into the battery charger code. Mhm.