Complex sentence: The second incarnation is the Joker himself, whose appearance and personality is very similar to the Silver Age version as drawn by Dick Sprang, in the episode "Emperor Joker!" along with Harley Quinn.
Split into simpler sentences: The second incarnation is the Joker himself, whose appearance and personality is very similar to the Silver Age version as drawn by Dick Sprang. He later appears in "Emperor Joker!" along with Harley Quinn.