Longbeard is a live action pirate who appears in the episode "Party Pooper Pants."
Longbeard appears in the episode when Patchy is introducing people at his party to the viewer. As Patchy is hosting a party in celebration of SpongeBob. Patchy introduces Longbeard by saying "Hey there Longbeard!, long time no see!" This seems to imply Longbeard and Patchy are likely friends.