Anti-Smooth

Anti-Smooth makes the server send entity updates more frequently to make player interactions with them (especially knockback from attacks) feel more responsive almost to a point that matches the behavior of mobs in true singleplayer from old versions before release 1.3.
This does increase the bandwidth used so it is best to only use this mod for singleplayer worlds, however mobs that are far enough away get interpolated with the vanilla method instead.
Additionally, knockback has been modified to be applied one tick earlier for better game feel. This can be disabled in the configuration for vanilla parity.

Anti-Smooth is available for 1.20.1+ on Fabric and 1.21.1+ on NeoForge.
If Anti-Smooth seems to not be available for newer versions, try using the mod jar for the most recent Minecraft version that it claims to support and if it doesn't work then please report it as an issue.

Anti-Smooth was inspired by No Mob Latency which does basically the same thing but there are some differences:

• What Anti-Smooth has over No Mob Latency:
  • Support for Fabric 1.20.1+
  • Direct support for NeoForge 1.21.1+
  • Distant mobs do not have instant updates
  • Knockback from attacks gets applied one tick early
• What No Mob Latency has over Anti-Smooth:
  • Velocity is applied client-side, though Anti-Smooth avoids this for simplicity

The source code can be found on Codeberg. Select different branches to see code for different versions of the mod.

Config

The configuration can be found in the "antismooth.json" file in the config folder.

{
  // When set to true, knockback gets applied a tick early.
  // It may be desirable to disable this if vanilla gameplay should be preserved.
  // Default value: true
  "instantKnockback": true,
  // The distance in blocks near a mob the player needs to be for Anti-Smooth to be applied.
  // Alternatively, setting this to zero removes the distance check
  // and every single mob sends a movement packet every tick regardless of proximity to players.
  // Default value: 64.0
  "checkDistance": 64.0
}