Child
Child, little one, baby, infant, young person, juvenile, teenager, stripling, son/daughter, wean, kiddie, tot, kiddiewink, young 'un, rug rat, babe, youngster, young one, toddler, boy/girl, minor, adolescent, youth, offspring, bairn, pickney, nipper, tiny, shaver, sprog, and ankle-biter.
Joke
Joke, jest, be facetious, play, fool around, wind up, rib, pull someone's chain, shuck, tease, chaff, pretend, fool about, pull someone's leg, have on, josh, and fun.