The bug

24w06a introduces minecraft:fall_damage_multiplier, an attribute that can be used to change how susceptible a given entity is to fall damage. Setting this to zero will forbid that entity from being damaged by falling. However, it being a greater value than zero will not permit mobs normally immune to fall damage to receive it, and mobs immune to fall damage have it set to 1.0 by default, which is unexpected.

Affected entities

• minecraft:blaze
• minecraft:cat
• minecraft:chicken
• minecraft:iron_golen
• minecraft:ocelot
• minecraft:snow_golem
• minecraft:wither

I am not sure if flying mobs, or non-mob entities, should be included here.

How to reproduce

1. Spawn a cat, ocelot, chicken or other mob unaffected by fall damage
2. Run the /attribute command to get its UUID and query its generic.fall_damage_multiplier value

Expected results

The value would be 0.0.

Actual results

The value is 1.0.

How to fix

Make all cats, ocelots, etc. susceptible to fall damage if the attribute is not zero, and have this attribute set to zero for them by default.