Let's start off with Adventure Time, the shows art style didn't go though as much of a drastic change as other shows. But there is an obvious difference, the earlier seasons have thicker outlines, brighter colors, and more cartoony animation. The designs in earlier seasons were more streamlined and less prone to go off model. Here's how Finn looks like in the earlier seasons, notice how his skin his paler. The lines are more bold. His head is very flat and rectangular. But his design is simplier, which is prone to rarely going off-model. Here's what he looks like now, not much of a change. However the colors are more shaded. He's also wobblier and chubbier. This causes his design to be very prone to going off-model. The lines are also thinner, and Finn's head is longer. Finn also has more of a tan. In early seasons, only are the lines thicker but the tint is different. Jake is more yellow-ish in early seasons, starting in Season 3 he's more bronze. Plus, in early season Jake is skinner and his jow is much much bigger. His ears are also larger. His design is also prone not never going off model. The old animation looks very odd after watching an episode from a later season, since I'm so used to the bulgier animation used in subsequent seasons. Jake's life is changing. Jake is chubbier his skin is bronze. His outlines are thinner. His jow is smaller. His desigined is less streamlined. And is very prone to going off-model. Jake also is much smoother. No jagged lines, everything is round.