How do I code a dog or bird to follow the player

I am making a wild west platformer and i want to give the player a pet that follow them around i don't know witch would be easy to code bird or dog but i want them to follow the player where ever they go and attack enemies for the player then come right back

you can set them to interpolate the player's position but create a variable so that if there is an enemy nearby it will attack the enemy, that is, it will only interpolate if there is no enemy nearby and you can regulate the distance by the interpolation time