slackbuilds_ponce/graphics/pencil2d

Pencil2D is an animation/drawing software for Windows, macOS, Linux, and
FreeBSD. It lets you create traditional hand-drawn animation (cartoon)
using both bitmap and vector graphics. Pencil2D is free and open source.

ffmpeg is runtime requirement. It's used to render mp4 and gif.
Otherwise you can render every frame to png.