Not only is it free and open source, it is quite good !!!
I’m pretty sure the same author does all the graphics for Framasoft, makers of PeerTube and Mobilizon.
searches
He apparently does some of their art, so probably whatever you have in mind was from him.
https://framasoft.org/en/credits/
The colour illustrations are painted by David Revoy and are licensed under Creative Commons By 4.0.
The comic characters drawn by Simon « Gee » Giraudot are licensed Creative Commons By-SA 2.0.
The penguins who walk around the site come to us from L.L. de Mars and are under Art Libre license.
The logo is a realization of AyM under license Creative Commons By-SA 4.0 It is inspired by the mascot initially created by L.L. de Mars.
He’s also on the Fediverse: @davidrevoy@framapiaf.org
His drawings are so cute
David Revoy is famous among open source artists. Dude’s put in tons of work.
