A frog in the throat of a frog dominates the discussion in this study:
“To have a frog in the throat: micro-CT imaging of anuran prey in Ceratophrys ornata (Anura: Ceratophryidae),” Thomas Kleinteich [pictured here], Salamandra, vol. 51, no. 2, June 30, 2015, pp. 209-211. The author, at Christian-Albrechts-Universität zu Kiel, Germany, reports:
“Frogs of the genus Ceratophrys are sit-and-wait predators that feed on a variety of different prey types, including spiders, insects, crabs, annelids, but also vertebrates like snakes, lizards, rodents, and other frogs. Among amphibian pet keepers, Ceratophrys spp. are often referred to as pac-man frogs on account of their ability to consume vast amounts of prey as well as relatively large prey items…. To overcome large prey, Ceratophrys spp. have wide mouths and heavily ossified skulls. However, besides of them being able to overcome and capture large prey items, it is critical for these frogs to fit large and bulky prey objects into their body cavity. Here I provide a first description on how large anuran prey is placed inside the body of a frog of the genus Ceratophrys by using micro-CT imaging.
“The specimen described herein is a 70 mm (snout–vent length) female Ceratophrys ornata housed in the herpetological collections of the Zoologisches Museum Hamburg, Germany.”
Here’s detail from the study:
BBC Earth has a nice report about the report, with the headline “The Pac-Man frog with a frog in its throat“.
BONUS (unrelated): “A frog in your throat or in your ear? Searching for the causes of poor singing,” Sean Michael Hutchins, and Isabelle Peretz, Journal of Experimental Psychology: General 141, no. 1 (2012): 76.
BONUS (mostly unrelated): Dead Duck Day at the Natural History Museum in Rotterdam.
BONUS (entirely unrelated): “Double-throat fixing type acute frog” Chinese patent #203741653, issued July 30, 2014.