For actors, drawing on influences around them to form a character in their own mind is simply a part of the method.
They can take inspiration from anything - other actors, famous people, sometimes even animals. In other cases, it can be famous musicians. Heath Ledger, for example, based his vocal performance for The Joker on Tom Waits.
For Iwan Rheon, best known for his chilling portrayal of Ramsay Bolton in Game of Thrones, he had a number of interesting influences - one of which was Heath Ledger's The Joker.
Speaking at a recent GoT convention in Texas, Rheon explained that Joker and Ramsay were similar in "how difficult he is to read, and how maniacal he could be and how he could just turn around and kill someone."
The other influence, Rheon said, was Liam Gallagher of Oasis. Wait, what? "I took the walk from Liam Gallagher, and his mischievous side from Dennis the Menace. Those were the three influences for Ramsay Bolton."
Whatever about The Joker, sure, that makes sense - but Liam Gallagher's physical presence doesn't exactly inspire dread in people. Unless you're a paparazzi, in which case Liam Gallagher's going to knock your lights out.
