CoolCat is an original Twitch.tv emote, which is available to all viewers/users on the site, without any addons to your browser like FrankerFaceZ or BTTV.
The emote features a picture of a red tabby cat wearing oversized purple glasses.
The emote can be used by viewers as a reaction to a streamer pulling off crazy-skilled gameplay or when you want to let them know, they did something cool, but want to be subtitle, while broadcasting live to Twitch.tv.
The origin and upload date of the image is unknown as there are no sources confirming it on the internet, however since it is part of the original Twitch.tv emotes collection, we can assume that it was uploaded in the past few years.
A drawn variant of the emote exists as part of the FrakerFacez collection, which is a browser extension that enhances your viewing experience on Twitch.tv, by adding new unique emotes, chat features, etc. to your liking.
As of 10/12/2019 according to the website StreamElements, CoolCat is the 61st on the list of most popular/used emotes on the website Twitch.tv, making it one of the more popular emotes.