One day; it was in a garden, with it's toe sticking out of the ground. The only child of the couple who lived there saw the toe, and for some reason he grabbed it and yanked it out of the ground! The poor monster gronned and went deeper underground. The child took the big toe into the house, and he and his barbaric family ate it for dinner! So, naturaly, the monster came back in the night and killed the little cannibal (what happened to the parents is unknown).
(Not counting the alternate ending) The story does not provide much description for the creature. Since it was underground (however) it might have been some sort of mole-like creature. It was also sentient, as it had the ability to inquire; "Where's my toe?!!".
There is an alternate ending to the "Big Toe". In this version; the boy finds the creature inside the chimeny. He asks it; "W-w-w-what you got such big eyes for?" (sound familiar?). The creature then replies; "To look you thro-o-o-ugh and thro-o-o-ugh!" (This sentence indicates; 1 The creature's probably not to good at English. 2 He is an underground creature with high quality vision. 3 He might have X ray vision.). The boy then asks; "W-w-w-what you got such big claws for?" (aparently he's not to good at English either). The creature then replies; "To scra-a-atch up your gra-a-ave!" (this again suggests mole-like features). The boy then asks; W-w-w-what you got such a big mouth for?" (this guy's doing a good job of scratching up his grave by himself if you ask me). The creature then replies; "To swallow you who-o-ole!" (at this, we have to assume that it was a very large creature). The boy then asks; "W-w-w-what you got such sharp teeth for?" (Is that a trick question?). The creature then replies; "TO CHOMP YOUR BONES!" (Now this doesn't help us much; 1 Many creatures have sharp teeth. 2 It counteracts the creature's threat of swallowing the boy whole.).
This version provides ample description for the creature by pointing out several of it's attributes, but it doesn't provide a complete description of it. However, by taking what we have to work with (including the fact that this ending is based on a scene in "Little Red Riding Hood), we get these possibilites; 1 It is a giant sentient mole (who may or may not have Xray vision. 2 It is a giant mole-man (who may or may not have Xray vision). 3 It is a giant sentient mole-wolf (who may or may not have Xray vision). 4 It is a giant mole-man-wolf (who may or may not have Xray vision). 5 It is a giant subterenial humanoid (who may or may not have Xray vision). 6 It is a giant subterenial man-wolf (who may or may not have Xray vision). 7 It is a giant sentient subterenial wolf-like beast (who may or may not have Xray vision). 8 It looks like it does in "Mouse Soup".
It is unknown what the monster did to the boy's parents. However; wether the monster wanted revenge, or to get it's toe back, or both, their chances of survival are slim.
In the movie Mouse Soup; the mouse reads an alternate version of the Big Toe. In this version the cannible people are mice. Also; it provides an illistrated description of the creature. It is a tall, thin, and distorted humanoid covered with green hair.
In this version; the creature doesn't eat the cannible mouse boy, because he had a bag full of toes to spare (flexible guy). However; we can't be sure that this version of the creature was good either. First of all; where did he get all those toes?