He giggled when he found out the identity of his enemy.
"It is a tree. Of course, it is a tree. How did I not see that coming? That ugly plant dragon should have clued me in. To think that I will fall because of a tree." He mused to himself sagely.
Then he laughed and laughed. His giggling turned into self-deprecating laughter pretty quickly. What kept him sane is the fact that either by chance or intention, this abode is located at the edge of the plane directly opposite the spot where the portal was created. It indicates that he didn't lose because of incompetence and that everything has been planned from the start so his loss to a tree is not so disgraceful.