Sentence:  "This little <WSD>froggy</WSD> took a big leap" / "This little <WSD>froggy</WSD> took a small" / "This little <WSD>froggy</WSD> leaped sideways" / "And this little <WSD>froggy</WSD> not at all" / "And this little <WSD>froggy</WSD> went," / "hippity, hippity, hippity hop, all the way home." 
Meaning of the word marked with <WSD> tags:  A frog.