Coming out either in late 1986 or early 1987 (the interior cover says 86, but it might have hit shops at the start of the next year), Temple of the Frog actually has much earlier origins, over a decade earlier in fact. 

Temple of the Frog was the first officially published adventure scenario by TSR all the way back in 1975 in the Blackmoor supplement to the Original 1974 D&D release. This is all before Arneson and Gygax became adversarial in terms of deciding who did what and owed what to whom when it came to D&D authorship. Now that Gygax is out of the company Arneson is publishing his Blackmoore scenarios through TSR again. 

To be fair to Gygax, however, before he left in 1985 he had already made some overtures to Arneson to bury the hatchet and get him to publish his D&D scenarios through TSR. So this is a continuation of that policy and here you get a really old-school adventure ins a more complete format than what could be found in 1975’s Blackmoor. You also have a wizard with a high powered laser sighted rifle on the cover ready to blow some kermits to kingdom come, so what’s not to like?