gifsicle manipulates GIF image files in many different ways. Depending on command line options, it can merge several GIFs into a GIF animation; explode an animation into its component frames; change individual frames in an animation; turn interlacing on and off; add transparency and much more.
You probably want imagemin-gifsicle instead.
$ npm install --save gifsicle
const execFile = require('child_process').execFile;
const gifsicle = require('gifsicle');
execFile(gifsicle, ['-o', 'output.gif', 'input.gif'], err => {
console.log('Image minified!');
});$ npm install --global gifsicle
$ gifsicle --help
MIT © Imagemin