The village sage from 'Bard: Mountain' resembles the elderly Summoner on the default profile banner in the game's client.
Bard will not intervene in battles unless the combatants themselves are the ones that could change the world for the worse. In 'Bard: Mountain' his focus was not the Noxian assault but rather the artifact being misused, which is why he didn't help the villagers.
In the Brazilian server it is called Bardo.
The Meeps will occasionally whisper upon spawning besides Bard.
Bard is Luke 'Rabid Llama' Rinard's first champion. He used to be part of Riot's Engineering team but later switched over to Design.
Bard was first extracted from the filenames of in-game icons and subsequently from promotional images.
Bards are usually poets or musicians dedicated to storytelling who either travel on their own or are hired by patrons and are dedicated to singing heroic tales or events past. This is why they often dress mostly in cloth or light leather and have a musical instrument handy for storytelling/singing in a light-hearted fashion.
Despite the name, Bard's theme was changed halfway from 'musical bard' (he even had an instrument) to 'cosmic being'.
The remnants of his musical theme can be seen on his flute-like weapon.
The way bards record history through songs and storytelling can be reflected in the way Bard aims to preserve the history of Runeterra. Additionally, both Bard and real-world bards are commonly depicted as nomads and pacifists.
In V5.3 five copies of Bard's mask were hidden across Summoner's Rift but have since been removed.
The first time they were encountered by a champion, they would glow and make a sound.
In Spectator Mode, they would light up when the camera focused on them.
Early in development Bard could decide what colour of meep he got once he had gathered enough chimes. Each colour of meep buffed Bard's spells instead of modifying autoattacks and they followed him around to show enemies which of Bard's skills Bard had upgraded. This was scrapped in favour of buffing autoattacks to increase clarity.
At one point in development Bard's ult used to fire a global range wave that silenced enemies it hit. 
Bard is an ethereal Celestial being who created a corporeal form in order to traverse and interact with the physical world.
This is obvious when looking at his wooden-peg legs, mask-face, and stitched arms. Not to mention that, when he dies, Bard's true form can be seen abandoning his body while it 'deflates'
Despite the lack of a physical form, Bard is not omnipotent. He can be banished and/or imprisoned by powerful magics, even so far as a force equally or more powerful possibly spelling his ultimate end.
Bard influences Runeterran history in a very different way compared to the Darkin. Where they seek to influence key events in history through conflict and bloodshed, Bard passively restores balance in Runeterra when its continued survival is about to reach critical levels.
Unlike Soraka caring for living beings and their peaceful coexistence, Bard focuses more on the bigger picture by attending to matters of cosmic significance and assessing their threat levels for Runeterra. As such petty mortals are not important, unless they threaten existence and reality themselves.
For example, Bard would save you not because you yourself are in danger but rather because your descendants will have a hand in keeping cosmic balance in the future.
The green ball that sits in Bard's weapon is a harmonic key that splits layers of reality and taps directly into the magical friction that all worlds emit.
Meeps are drawn to him. Even though they are capable of surviving on their own, they've traveled with Bard for so long they've formed a symbiotic bond.
Bard's manner of speech is a way to keep the information he gives a secret.
For example, if he were speaking to you you would think he speaks your language just fine, but in reality that is the case for you alone because you are meant to receive the message. If someone were to eavesdrop on the conversation they'd hear something akin to his in-game voiceover, an intentional move on Bard's part.
Bard is the second champion to have both a voiceover with no actual spoken words as well as a music-themed one, the first for each being Rek'Sai and Sona, respectively.
In 'Bard: Mountain' the village sage implies his people will 'die without' the artifact Bard snatched from him. This was not the case, for one of the children residing in the Noxian-assaulted village grew up to become the elderly storyteller from 'The Wonder Above'.