The gist of it is this: Fall Out Boy licensed some llama puppets for their music video for 'Young And Menace.' And ONLY for that music video. However, the puppets have been featured on band merch, at tv appearances, at live shows, and have been turned into emojis. Yeesh.
The company that made and licensed the puppets, Furry Puppet Studio Inc., is suing the band for damages and asking for a court order to stop them from using the puppets outside the original bounds of the license in the future. Consider that bridge burned.