Jeremiah Valeska dons a purple overcoat and long brim fedora which bears a striking resemblance to the classic Joker design, who was often drawn wearing an eccentric purple fedora and trench coat.
At 28:14 there is an error in the English caption. The Scarecrow says "The experiment is nearing its conclusion" but the caption has "it's (contraction of 'it is') rather than the proper "its (belonging to it)".