Yeah lets avoid this whole argument before it starts up with anything serious with some size records that i know, as well as a little background info on some stuff....
First off, Carnivoure12- Venus Flytrap has become more of a general name for any carnivorous plant, many times ive taken Nepenthes to school and had students call them Venus Flytraps, most people generally dont know that there are other names like pitcher plants, sundews, bladderworts you know...
Nepenthes - the ONLY nepenthes documented to catch a mammal without the help of a human is rajah? Not true, its happened in greenhouses many times with other large neps, or nep hybrids. However the only WILD documented case is with a rajah, AFIK.
Venus Flytraps (Dionaea Muscipula) - Check out CPUKforum for their largest dionaea trap of the year contest....many people have trouble getting them anywhere near 2"...and those do not eat mammals...the only non arthropod thing ive seen them eat are small frogs/lizards and even then the traps generally rot off.
Sundews - depending on the variety, can range from a small pygmy dew the size of a penny, to say...2 feet in diameter like the mighty Drosera regia. But cannot eat anything near the size of even a small frog. unless it is one of those incredibly tiny ones, dont remember the name....
Pinguicula - like sundew vary greatly however are really no good at trapping anything other than small insects (Ants, flies, gnats, mosquitoes, etc)
Bladderworts - catch microbes or small aquatic/soil insects like say...springtail or daphnea...or larva gnats....or mites even, but nothing big at all. too small.
Sarracenia and Darlingtonia - Sure, can grow a few feet in height given proper sunlight and conditions, but generally eat nothing more than insects from small ants or gnats, to bees or wasps...i have however, found a frog or lizard in a couple pitchers, though its rare for me up here...
Cephalous follicularis - feeds also mainly on small insects and gets nowhere on the large scale, although it clumps up like mad if grown in the right conditions
Heliamphora - also, mainly feeds on small insects, and only one species AFIK has been known to produce its own digestive enzymes, like Darlingtonia or a couple variety of sarrs, it relies on bacteria to break down its food to then absorb it...
You get the general idea, im not going to go any farther LOL i just felt like i should post some long, boring post before i left for a couple weeks tomorrow.
But basically, there is no VFT larger than your hand, there is no VFT that can eat rodents....
if of course, we are actually talking about Dionaea.
EDIT: Pitcher size, to name a few of the largest neps here
N. rajah - known to get around 2 feet on occasions
N. truncata - two varieties, lowland and highland...lowland is the largest AFIK, with a pitcher measured at 24" on the dot from base of pitcher to tip of lid.
N. macrophylla
N. xTrusmadiensis
N. merilliana
and some manmade hybrids that get huge
N. lowii x truncata
N. truncata x xTrusmadiensis
N. xCaeser
N. xPredator get some decent size to it
these are just a few, but youll notice a trend to it....mainly the plants that are listed above, are in the largest hybrids as well.