The name of a Lego set in the Mixels line. Part of his description read: "Part chicken, part frog, part back-of-the-bus window licker...", which seems fine to
people in the US, but over in the UK, window licker is a term for mentally disabled
people. The name itself, however, comes from turgid, which means distended, which roughly matches his appearance both in the animated series and Lego set.
TL;DR: Lego Mixel offends UK after being described as a window licker, slang for
retarded in the UK.