Disclaimer: this was made in 30 minutes as I was bored during a university lecture.

Features:

• Spawns a tamed wolf for every player upon login.
• Gives the wolf regeneration and speed to beef it up a bit.
• Ensures the wolf stays by the player's side all the time.
• Respawns the wolf after 5 seconds if it dies.
• Removes the wolf when the player quits the server.

Commands:

• None.

Configuration:

• None.

Future improvements:

• Make respawn time configurable
• Add wolf nametags DONE
• Make code less lazy

That's all folks!