The tongue had a pink colour and the ventral side of the body was light yellow.

Leguat described the species: There's another sort of nocturnal lizard of grayish colour, and (very) ugly; they are as big and as long as one's arm, their flesh is not bad, they love (being on) plantanes (latan palms).

P. gigas was last collected in 1842 on the offshore islet of Ile aux Fregates.

P. gigas became extinct due to human-induced deforestation and predation by introduced cats and rats.

As observed in other species of day geckos, it was assumed that P. gigas also liked to lick at soft, sweet fruit, pollen and nectar.