List of Cosmere Shapeshifters

Physical change through unknown power, possibly inherent

Dragon (cosmere) - can appear human and possibly other forms as well
Sleepless (Dysian Aimian) - passable but easy to spot on close inspection (hordelings)
Siah Aimians - possibly limited, related to cognitive realm (shadows)?

Dakhor - see Dilaf
Elantrians - sort of, but they are generally still recognizable, even during the Shaod or away from Sel (see ^[1] and ^[2]). Members of the Ire do not age at the normal rate^[3] and can become so old that they no longer appear to be normal humans.

Kandra - Hemalurgy - need bones to look human
Returned - when they come back, they look totally different; after that they can change appearance but not total shapeshifting
- It seems that some non-Returned can do this possibly with enough Breath or training, see Vivenna or this wob^[4]
- Royal Locks - hair only
Forgery via Essence Marks
Feruchemy can store a large amount of youth in an atiummind, enough to change the person's appearance to a much younger version of themselves (particularly if Compounding is involved), see The Lord Ruler or Marsh
Aethers include a physical manifestation, but it's not really canonized

Lightweaving, possibly through different types of Investiture
- Order of Lightweavers uses Surgebinding, e.g. Shallan; this is not limited to themselves
- Order of Truthwatchers also have Surge of Illumination but has not been used on-screen
- Hoid uses a version that originated on Yolen

Spren - ability to change shape and appear near-human varies widely by spren type (and Nahel bond)
- Unmade - similar to above, depends on which one
Seons change shape while communicating, and have other similarities to spren which would likely allow shapeshifting
Shards can appear to humans in different forms
Speculatively, other potential God characters such as Adonalsium or the God Beyond could take different forms in the Physical Realm

Parshendi and Regals can take different forms but are still identifiable
Numerous characters are simply good at disguise, such as Kliss, Wayne, and Liss
Svrakiss are thought to be able to possess other individuals
Members of the Seventeenth Shard slow their aging through an unknown method, which would influence their "natural" appearance^[5]