little foot is 100,000,000,000,000,000,000,000,000,000,00010,000,000,000,000,000,000,000,000 (100 nonillion to the power of 10 septillion), which is equal to 103.2*1026. This name was given by Sbiis Saibian after a Googology Wiki user "Vilius2001" gave this number in an attempt to approximate BIG FOOT. Saibian coined the name in mockery of this number (jokingly calling it a "lower bound"), which is of course not at all close to BIG FOOT.
BIG FOOT can not be described by any practical means using decimals, exponents and power towers, like most of the higher numbers in googology. More to the point, little foot is smaller than a googolplex (it falls at around 101026), and so is smaller than the majority of googologisms.