Kobold Avenger
Legend
They're similar in that they all come from a variety of animals as opposed to a specific ones (like the Tabaxi and Kenku).
Ardlings being from the Beastlands are based more on the conceptual idea of animals, or alternatively be seen as "lets play a full on furry", and they toned down the celestial bit.
Shifters are sort of Lycanthrope/Werewolf-lite, and might be the most tied to the Material Plane of the bunch. I guess they can be seen as "part-time furries" by some.
Hengeyokai which haven't appeared in 5e yet, are more like Spirit Animals who can become Human-like. They're probably Fey, and related enough to the Celtic Pooka/Puca/Puck that they might be the same thing with a different name.
Ardlings being from the Beastlands are based more on the conceptual idea of animals, or alternatively be seen as "lets play a full on furry", and they toned down the celestial bit.
Shifters are sort of Lycanthrope/Werewolf-lite, and might be the most tied to the Material Plane of the bunch. I guess they can be seen as "part-time furries" by some.
Hengeyokai which haven't appeared in 5e yet, are more like Spirit Animals who can become Human-like. They're probably Fey, and related enough to the Celtic Pooka/Puca/Puck that they might be the same thing with a different name.