Answer:
He stayed with and accepted help from Beorn, who can change into a bear.
Explanation:
Bilbo, Gandalf, and the dwarves stay with Beorn for a few days. In that time, Beorn comes to like them due to their shared enemy (Goblins). They later left Beorn's house and traveled three days before they arrived at the edge of Mirkwood. Bilbo noticed that a bear still followed them.
<h3>
Answer: No, it is not a run-on sentence</h3>
This is one full thought that doesn't run on for too long. The "overcome with joy" portion is the dependent clause that needs the other part "Mrs. Monroe told her husband the exciting news about her promotion" which is the independent clause. The independent clause could be its own sentence without the dependent clause, but not the other way around.
Plot twist you have schizophrenia