The drinker is apparently so named due to the habit of the larvae sucking up water droplets after rainfall. This particular caterpillar was found amongst the grassy dunes near a beach in Northumberland. It pupates on grass stems in a yellowish cocoon (unfortunately didn't take a photo of one of these) that look similar to that of a Burnet moth. The imago (adult form) is pale brown in colour.
This is the larvae of the Lackey Moth. I fell in love with these iridescent tent caterpillars, after seeing them on a warm May day near Marloe Sands in Pembrokeshire. They form vast silken tents for temperature regulation on hawthorn and blackthorn. The imago, by comparison is a dull brown colour.