minecraft-packets/minecraft-packets/data/pc/1.16.5/from-server/entity_update_attributes/2.json

An easy way to query PrismarineJS/minecraft-packets

{
  "entityId": 145,
  "properties": [
    {
      "key": "minecraft:generic.movement_speed",
      "value": 0.25,
      "modifiers": []
    }
  ]
}