It is indeed a Ki-rin
Jeremy Crawford has stated in a tweet as a response to someone posing this same question:
Casey White @CaseyDaWhite
@mikemearls @JeremyECrawford Not sure who to ask, but what is the familiar sitting on the War Mage's shoulder? (Pg 59 of Xanathar's) I've been pouring over the monsters and can't find anything similar.
This depicts Orcus raising Cyrog from Out of the Abyss
Warning: this answer is full of spoilers
During the Out of the Abyss adventure, the party travels to a location called Gravenhollow, a library that, among other things, allows the party to experience visions of events of the past, present and future.
The relevant section from Out of the Abyss is "...
These particular symbols date back to the AD&D 2nd edition revised Player's Handbook (1995), where they appear in an elaborate diagram in the specialist wizard rules depicting the eight opposing schools of magic. The revised 2e rules added a large amount of all-new art, so that what was a simple drawing of crossed lines in the original AD&D 2e Player'...
Under the usual proviso of "spells only do what they say they do", then there is no indication in the spell description that the mage hand is visibly connected to the caster.
As you quoted yourself:
A spectral, floating hand appears at a point you choose within range.
There is no reason to believe there is any other visual effect. (Though ...
Fair warning: this answer does not include any actual knowledge of the history of these symbols’ usage in D&D, nor any statements from D&D authors responsible for choosing them. Instead, I am trying to match these symbols to those found elsewhere. Several of them seemed to remind me of alchemical and astrological symbols as used in Europe since Greek ...
No, the image doesn't reference mage hand and the spell doesn't describe it working like this.
I honestly never would have thought this an option before seeing that picture. The written description seems clear (see below) and the illustration shown in the question doesn't say what spell/ability it is depicting. It has no title, no label, no description. ...
It appears to be a Berbalang
Looking through the pictures in Mordenkainen's Tome of Foes it most looks like the Berbalang.
Wizards of the coast has been known to put baby pictures of monsters in their books.
As such I suspect it's a baby Berbalang. For reference a Berbalang looks like this:
This is one of the "portentous runes & glyphs" from the World of Greyhawk boxed set. Here's a pdf of the page on Greyhawk Online (go to the end). It means "uncertain, questionable." Also known as Gygax's rune system, they found their way into many AD&D adventures and such. Greyhawk wise, they appeared on p29-32 of the 1980 Folio, p17 of the Guide, ...
This DM screen was released in August 2008, a couple of months after the first PHB, MM, and DMG were released (June 2008). MM2 and PHB2 weren't out until 2009 so this likely features exclusively MM1 monsters. It was illustrated by the late Francis Tsai, whose signature can be found in the lava in the bottom right.
Characters in the image are ...
They don't usually wear that many, but generally speaking, Rogues are the stereotypical "prepared for everything" character. They need belts because belts means pouches and other storage locations for stuff. And they have lots of stuff.
As a Rogue, you need room for lockpicks, skeleton keys, daggers, trap-disabling tools, smokebombs, caltrops, coins and ...
Turn back one page from the Acolyte Background
The art on PH p. 125 (the first page of the Backgrounds section) seems to depict an acolyte. The figure carries a mace (commonly associated with clerics in D&D) is touching what appears to be a holy symbol brooch, and is wearing a white cloak.
Several similar character sketches throughout the Backgrounds ...
Most likely The Great Drunkard
These are the Walking Statues of Waterdeep:
The God Catcher
The Sahuagin Humbled
The Great Drunkard
The Lady Dreaming
The Honorable Knight
We can immediately rule some of these out by their descriptions or by images already presented in Waterdeep: Dragon Heist, leaving us with:
This is the symbol for the magic school of Abjuration. You can see it on a lot of different items in the 5E DMG, all of which function by protecting the user in some way: the Ring of Protection, the Scarab of Protection, and the Spellguard Shield, to name a few.
Since 2015, the symbols for magic schools have increased in visibility. They're used ...
These are the characters described in "Choose Your Villain(s)," in the introduction:
The beholder looming behind is The Xanathar,
the eyepatch- and large hat-wearing drow is Jarlaxle Baenre,
the human couple are Victorio and Ammalia Cassalanter, and
the hooded figure is one of Manshoon's clones.
And piled around them are pictured, of course, the eponymous ...
In Playing at the World, historian Jon Peterson suggests that both Orcus and Demogorgon originally found their way into D&D via Milton's Paradise Lost.
Above these rank-and-file fiends rule the Demon Princes, Orcus and Demogorgon, unique monsters who previously shared a couplet in Milton’s Paradise Lost (“Orcus and Ades, and the dreaded name/Of ...
There are many character creators for fantasy games in computer gaming.
The PC versions of many RPGs have extensive character creators. The Dragon Age series, and the World of Warcraft game have extensive customization options.
There is also the custom miniature creator HeroForge - https://www.heroforge.com/ which is designed to let you visualize your own ...
You could actually use the AutoREALM icons, if you don't mind a bit of fiddly work.
It is quite easy to vectorize simple graphics. Inkscape (free alternative to Adobe Illustrator) has such a function to trace bitmaps by various attributes of the original image (colour, brightness, edges and so on). You can make a map that's just the AutoREALM icons you want ...
That picture is a warrior trapped in a flooding room while attacked from behind by a skeleton. It appears in separate depictions by different artists in AD&D 1st edition, AD&D 2nd edition, and D&D 3.0:
AD&D 1st edition DMG (1979), page 68. David S. La Force
AD&D 2nd edition revised DMG (1995), page 95.
D&D 3.0 DMG (2000), page 114. ...
Oddly enough, the game Space Marine is a fairly good source for this in the audiologs. You find journal entries by various people including a number of random citizens, which I find really drive home what an ork invasion means, and give you glimpses into what they live through. I bet you could find them on youtube.
Also, you walk through a number of ...
The Dark Heresy line has some material; it tends to focus more on the powerful - nobles, etc, but there are a few bits of the seedier side.
The Rogue Trader corebook and it's player's guide have pretty good descriptions of the lifestyles of normal ship crew, but I suspect that's still unusual enough to be out of scope.
The real images of the lower class ...
Starting on the left, row by row:
This leaves Talons and Ruin as the two unrepresented cards in the illustration.
According to In the Cage  a AD&D 2e source book, Sigil's architecture is described as follows:
Sigil's a city overwhelmed, barnacled, and encrusted with buildings. With a 5-mile diameter and 20-mile circumference (as officially measured by the Harmonium; in actuality, the Lady can enlarge or shrink the city as she wills, at any time), Sigil's huge, ...
There's no such thing as a single "official" acolyte appearance — an acolyte is just a low-rank or trainee priest. Use any art for a cleric that suits the specific NPC and religion you desire to portray.
The D&D Beyond versions of the books include all art from those books
The compendium content of each adventure on D&D Beyond is an online browsable version of that adventure. It contains not only the adventure text, but also cross-links and tooltips for monsters, mundane or magical items, spells, and relevant rules mentioned in the text... But most ...
There is a free web-based tool called Hero Machine. It has several versions -- modern, superhero, and fantasy, at least -- and does exactly what you're after. Character images are stored as text strings that allow the Hero Machine to recreate the illustration when reloaded, though you can also use a screen dumper or print-to-file to save an actual image ...
No one will care about your game in 35 years. You will be lucky if they care about it in 3 years. If they do care about it in 35 years, doubtless you will have a new version with new art. D&D isn't still using the same illustrations from 35 years ago now are they?
Many people, and I see this in the tech startup world all the time, get wrapped around ...