This cute little character is pedobear , and he is one of those internet memes that may have escaped your notice. Basically it is a way to be really offensive without offending the unaware. It somehow has come to reference or allege pedophilia without overtly stating it. For example you might see a cartoon of pedobear in pope garb. Someone has been tagging with the image in Manhattan for the lulz.
Two of my favorite artists, R. Crumb and Stikman together at last. At first I was thinking that it was someone else appropriating the work of both artists, but Stikman is known to use R. Crumb images, so my guess is that it is a genuine Stikman sticker. It is possibly rererencing people collecting street art. Notice that someone has tried to peel this sticker.