There is a many ways to play another animation when a animation ends
In editor

Using queue
get_node("AnimationPlayer").queue("New Anim (2)")
Using signal
get_node("AnimationPlayer").connect("finished", self, "do_anim_finished")
or
var anim = get_node("AnimationPlayer")
anim.connect("finished", anim, "play", ["New Anim (2)"])