Gavin at City of Iron came up with this idea of a table to explain a character's disappearance between gaming sessions. Here are my contributions:
25. Turned into a guard dog with same number of hit points as character in normal state. If spellcaster, can only cast single-finger somatic cantrips using tail.
26. Character disappears and is replaced with life-size parchment cutout illustration of the character.
27. Turned into a turnip and placed in the cook's supply bag.
28. Transmogrified into eight year old boy in short pants dragging stuffed tiger, both of whom refuse to speak with the party.
29. Turned into inanimate statue melded to floor. Any attempt to chip away at statue will result in appropriate damage to character's feet next game session.
30. Turns out the character was never with the group to begin with--it was all a dream.
31. Turns into a hat. Hat may be worn by another party member and provide an appropriate AC bonus equal to one third the character's normal AC (round up).
32. Accidentally frozen in magical ice by Wixard the Wise, absent-minded professor of dungeon physics, who was experimenting with spell sending using a scrying crystal and hit the character by mistake (he thought the area was deserted and was aiming for some nondescript feature of the room).
x x x
97. Ate a bad pork rind; took sick to bedroll.
98. Sliced artery whilst trimming beard; off seeking medical help. Party cleric(s) refused to heal because, really, who trims their beard?
99. Stumbled upon flail snail mating ritual and was so absorbed lost track of time.
100. Off churning the buttermilk, if you know what I mean.