Tickling Saint Anthony
This altarpiece was probably commissioned for a church or guild honoring Saint Anthony Abbot, traditionally a fourth-century Egyptian hermit, one of the "Desert Fathers" of the early church. (There's a lot more information about him here.) The two painted panels on the innermost wings of the altarpiece show, on the left, the visit of St. Anthony to his good buddy St. Paul of Thebes, another of the Desert Fathers, and on the right, St. Anthony's temptation by demons. Here's the left panel:
And the right one:
And, for completeness, a closer view of the statue of St. Anthony -- note the pig nestling under his robes on the right, and another held by his follower:
Saint Anthony is distinguished by a Tau (T)-shaped or sometimes L-shaped staff. This is actually an early version of the more familiar curly-headed bishop's crozier. The crutch-like shape may also relate to the fact that St. Anthony is almost always shown as a very old man.
The "Temptation of Saint Anthony" is one of those classic scenes artists seem to have really enjoyed painting, perhaps because it gave them carte blanche to exercise their imaginations and dream up some really interesting demons. The moral of this story is that being alone in the desert doesn't eliminate the possibility of sinning, it's just that it comes to visit you instead of you having to go look for it. Hieronymus Bosch painted the scene several times, with his usual weird creatures in the background (for instance here and here), though for some reason most of those directly tempting St. Anthony in this case appear to be human. Jan Wellens de Cock, Pieter Bruegel, Bernardino Parenzano, and Lucas van Leyden were other examples I could readily find, with the last-named having particulary interesting creatures on offer. But Grünewald's version in the Isenheim altarpiece has them all beat.
As you can see in Grünewald's Temptation panel, the demons are combinations of animal parts and nightmare, and there's a bit of confusion about exactly which parts belong to whom where they are all jumbled together. They are pulling the saint's hair, threatening to beat him with sticks and making terrifying faces (not that they can help that last part).
As you might expect, my attention went straight to the saint's right hand, which something with a bird beak is trying to bite. In that hand you can see he is holding his staff and also a string of beads:
As beads, there is nothing particularly remarkable about them; we can see just five plain round red beads. Being red, they are likely intended to be coral, which was probably not popular with fourth-century hermits but very popular with those who could afford them in 15th-century Alsace.
It's really the expression on Saint Anthony's face that I find the most intriguing thing in this picture. I am no art historian, so I don't have a good feel for how fifteenth-century painters depicted facial expressions; it's entirely possible that this particular expression means something I'm not aware of. But to me, it looks as though Saint Anthony is laughing, or perhaps giggling. I suppose this is as good a reaction as any when one is being tempted, especially when one has no intention whatever of giving in.
Or perhaps the demons have been given Supernatural Tickling Powers. Oh horrors.