Spiff encounters the blob.
The blob prepares to eat Spiff.
The blob of gelatinous muck is a creature in the Spaceman Spiff universe that appeared in a single Sunday Strip. It was encountered on a "distant world" with a noxious atmosphere by Spiff, and manifested hostility by trying to eat him. As per usual, Spiff's weapon (here referred to as the "Blaster") proved useless against the otherworldly nemesis.
The comic ended with Calvin in his school cafeteria lamenting the lunchroom tapioca, the blob's real-life counterpart and inspiration.