The pilot episode for Pickle and Peanut, "Greg", had a different animation style than other episodes, as the pilot was animated by Mercury Filmworks, and the rest of the episodes was animated by Copernicus Animations.
The pilot episode for Pickle and Peanut, "Greg", had a different animation style than other episodes, as the pilot was animated by Mercury Filmworks, and the rest of the episodes was animated by Copernicus Studios.
There is actually no reason that why Peanut wears a headband. This is shown in the pilot episode.
In the pilot episode "Greg", this was the only episode with animation services by Mercury Filmworks, rather than Copernicus Studios Inc.