Professor Pendulum

 Professor Peter P. Pendulum is the scientist and inventor of two time machines - one for the future, one to the past. While his native island is Time Tangled Island, he only appears in person on Shark Tooth Island in the Tourism Center, along with a similar looking female character. He is essentially the cause of the time machine mishap, although unintentionally.

Characteristics
Professor Pendulum has yellowish skin and brownish hair. He's adventurous and tends to get himself in trouble. After successfully making a time machine, he wears a huge smile as shown in the picture. While his character type is indifferent, he is friendly and doesn't have any apparent bad motives. He's very studious and likes to learn and discover.

Role in Time Tangled Island
According to a newspaper you can read on Time Tangled Island, Professor Pendulum had just recently created two successful time machines - one for the past, and one for the future. In celebration of his success, he's taking a trip to Shark Tooth Island.

Role in Shark Tooth Island
You will find him in the Tourism Center on Shark Tooth Island. His appearance there is one of the few displays of Island Continuity.

While he doesn't have an apparent evil agenda, his time machines are what puts the entire world in peril. You as the player have to go back in time and fix mistakes that Professor Pendulum caused. He appears to be unaware of the whole incident as he is on vacation.

If you meet him in the Tourism Center, you will also find a similar looking female character above him. She has the same skin tone and hair color as him. You can read more about her here. She is presumed to be some sort of relative to Peter.

He has not appeared anywhere other than the two times in the game listed above.

Trivia

 * He is the second Poptropican to appear on two islands (excluding characters from Wimpy Wonderland Island and Wimpy Boardwalk Island and the villains from Super Villain Island) the first being Leonardo Da Vinci and the third being Thomas Edison.
 * There is another woman in the Shark Tooth Island Tourism Center who looks extremely similar to him. This could be his wife, daughter, or sister.
 * Peter's name is a play on the word pendulum. A pendulum is a weight suspended from a pivot so that it would swing freely. It is often associated with the subject of physics.
 * His name also is alliterated, meaning that all the words start with the same letter - in this case the letter p - Professor Peter P. Pendulum.