He seems to be back to normal - at the worst we had the 'gagging', copious drool/nose snot (all clear, but very thick), slitted eyes, less coordination than normal, an intense focus on whatever was going wrong (so little interest in the world beyond him), and a definite feeling in both of our guts that something was wrong.
No more drooling/whatever, no more gagging, showing a lot of interest in the outside environment, passed the Cheerios test with flying colors and also protected his cheerio from Cera (who'd finished hers and thought she'd take his - we grabbed her but only after Mr. Honeycomb had sidled away from her once or twice, he did finish it though!). The Pips each decided to help clean his chin, and came over a few extra times to see if his chin needed more cleaning, but of course it hasn't (which is a good sign).
Lord knows what this was... besides very very scary. Tim's still upset over it and keeping a hawk's eye on Mr. Honeycomb.