bedrock-samples/resource_pack/particles/oozing_emitter.json

{
  "format_version": "1.10.0",
  "particle_effect": {
    "description": {
      "identifier": "minecraft:oozing_emitter",
      "basic_render_parameters": {
        "material": "particles_alpha",
        "texture": "textures/items/slimeball"
      }
    },
    "components": {
      "minecraft:emitter_rate_instant": {
        "num_particles": "math.random(2, 4)"
      },
      "minecraft:emitter_lifetime_looping": {
        "active_time": "math.random(0.1, 0.8)"
      },
      "minecraft:emitter_shape_point": {
        "offset": [0, 0, 0]
      },
      "minecraft:particle_lifetime_expression": {
        "max_lifetime": 1
      },
      "minecraft:particle_initial_speed": "math.random(1,2)",
      "minecraft:particle_motion_dynamic": {
        "linear_acceleration": ["math.random(-2, 2)", "math.random(-2, -10)", "math.random(-2, 2)"]
      },
      "minecraft:particle_appearance_billboard": {
        "size": [0.0625, 0.0625],
        "facing_camera_mode": "lookat_xyz",
        "uv": {
          "texture_width": 16,
          "texture_height": 16,
          "uv": ["Math.round(variable.particle_random_1 * 12.0)", "Math.round(variable.particle_random_2 * 12.0)"],
          "uv_size": [4, 4]
        }
      },
      "minecraft:particle_motion_collision": {
        "collision_drag": 10.0,
        "collision_radius": 0.2,
        "expire_on_contact": true
      },
      "minecraft:particle_appearance_lighting": {}
    }
  }
}