Aroga's Hound of Many Arrows

You conjure Argos the watchdog in an unoccupied space that you can see within range. You can conjure Argos in two forms: 

Sentinel Mode: 

Once casted he can be seen and interacted with, but his movement is limited to a slow walking speed of 15 feet/round. In sentinel mode Argos will bark at anyone who does not know the password for the person he is protecting. 

You can use one action on your turn to change him to Attack Mode: 

Once changed to attack mode he immediately goes invisible. At the start of subsequent turns, the hound attempts to bite one creature within 5 feet of it that is hostile to you. The hound's attack bonus is equal to your spellcasting ability modifier + your proficiency bonus. On a hit, it deals 4d8 piercing damage. 

Argos can see invisible creatures and can see into the Ethereal Plane. It ignores illusions