Bowser assigned Hoo to guard one of the Toads he captured in Hoo's Wood. Princess Peach arrived at his bridge and fought him. Eventually they both began a long fall, but in the end, Peach won and Hoo fell to his doom.
In his battle intro, Hoo swoops down and snatches the Toad inside the bubble.
He attacks by throwing eggs at Princess Peach, which hatch into baby owls, which can be killed with any regular attacks. He then swoops down at Peach. At that point, she can jump on him to damage him.
He has five hit points, and jumping on him three times causes him to start using the Joy Vibe, which leads to him throwing a bunch of eggs at the platform Peach is standing on and breaking it, sending her falling to the ground with Hoo flying after her.
Hoo must be hit on the head twice, though the only way for Peach to go above him is while using her own Joy Vibe, which lets her hover above him. However, Hoo shields himself while Peach is using the Joy (or Rage) Vibe, requiring her to to deactivate it while above him. After being defeated, Hoo falls and lands on the ground and disappears forever in a whirlwind, which includes minor leaves.
Hoo is one of three bosses original to Super Princess Peach. The other two are Blizzaurus and Army Hammer Bro. All the other bosses appeared in previous games except the Wiggler, though many of his species have been seen previously as well.