Timotei wanted to show Marceline that life was much harder than she thought it to be and not to underestimate him. The vampiress was a problem. She had upset him by trying to throw him out of the mansion.
The black cat then scrunched his nose and his whiskers. He opened his mouth, "RAAAAAWWWWRRR!" Wow, he couldn't believe his throat had such power, Timotei thought to himself.
This was enough for the coachman to pull the reins of the horses, getting them to start galloping, and he quickly left the place along with the carriage as fast as he could to save his life.
Timotei couldn't help but snicker. He said to no one, "I will see how you will be able to get back to the mansion, Lady Marceline. Might as well take a nap with the dead witch."