They can either be wood or aluminum. I encourage you to use a wood one. If not, I will make fun of you like I do my good friend Bill Booker at LaSalle-Peru H.S. for using his aluminum one. If you choose the wood fungo, I would recommend taping the barrel.  If you hit a good number of fungoes, the tape will increase the durability of the bat. I took the tape off of one once. The barrell was like sawdust, but I re-taped it and it was ready to go.  One season, I figured it out, between the  high school, American Legion, an junior high seasons I had hit over 10,000 fungoes. Tape it up!
Whether you’re looking for youth league or adult league solutions, our selection of baseball gear offers everything you need to kick off the baseball season with your best foot forward. We carry nothing but the finest baseball mitts and gloves available made by Wilson®, Mizuno®, Louisville®, and other brands trusted by professional baseball players and coaches. Carry your gear to the diamond with ease with the help of our sleek and stylish backpacks, equipment bags, and duffels.
The origin of the word "fungo" is unknown and argued upon as there are many possible options as to the origins of this unique word. It is assumed by many to be derived from the Scottish word fung meaning to pitch, toss, or fling. This would make sense, as fungo bats are designed to do just that. Or, the alternative to this origin is that fungo comes from 1937 where David Shulman, writer for the American Speech, said, "My guess is that the word, which is baseball slang, may be explained through the elements of a compound word, fun and go." Lastly, a third belief is that the word fungo comes from an old game, similar to that of baseball, where the players used to chant, "One go, two goes, fun goes." 
Within league standards there is ample latitude for individual variation, many batters settling on their own bat profile, or one used by a successful batter. Formerly, bats were hand-turned from a template with precise calibration points; today they are machine-turned to a fixed metal template. Historically significant templates may be kept in a bat manufacturers' vault; for example, Babe Ruth's template, which became popular among major-league players, is R43 in the Louisville Slugger archives.[citation needed]

Fungo bats have been around since the beginning of baseball and as most of us may know, baseball was said to be invented by Abner Doubleday in Cooperstown, New York during the summer of 1839. Since fungo bats were much easier to swing and gave off a ton of pop, they were almost seen as cheating back in the day. In a book from 1897 named "The Technical Terms of Baseball," the sportswriter Henry Chadwick stated,"The weakest batting is shown when the batsman indulges in fungo hitting." It wasn't until baseball bat regulations came around that fungo bats were only used by coaches and parents. 

Within league standards there is ample latitude for individual variation, many batters settling on their own bat profile, or one used by a successful batter. Formerly, bats were hand-turned from a template with precise calibration points; today they are machine-turned to a fixed metal template. Historically significant templates may be kept in a bat manufacturers' vault; for example, Babe Ruth's template, which became popular among major-league players, is R43 in the Louisville Slugger archives.[citation needed]

A baseball bat is divided into several regions. The "barrel" is the thick part of the bat, where it is meant to hit the ball. The part of the barrel best for hitting the ball, according to construction and swinging style, is often called the "sweet spot". The end of the barrel is called the "top", "end" or "cap" of the bat. Opposite the cap, the barrel narrows until it meets the "handle". The handle is comparatively thin, so that batters can comfortably grip the bat in their hands. Sometimes, especially on metal bats, the handle is wrapped with a rubber or tape "grip". Finally, below the handle is the "knob" of the bat, a wider piece that keeps the bat from slipping from a batter's hands.
Both wooden and metal alloy (generally aluminum) bats are generally permitted in amateur baseball. Metal alloy bats are generally regarded as being capable of hitting a ball faster and farther with the same power. However, increasing numbers of "wooden bat leagues" have emerged in recent years, reflecting a trend back to wood over safety concerns and, in the case of collegiate summer baseball wood-bat leagues, to better prepare players for the professional leagues that require wood bats. Metal alloy bats can send a ball towards an unprotected pitcher's head up to 60 ft 6 in (18.44 m) away at a velocity far too high for the pitcher to get out of the way in time. Some amateur baseball organizations enforce bat manufacturing and testing standards which attempt to limit maximum ball speed for wood and non-wood bats.[17][18][19]
Fungo bats are typically only used by coaches, to consistently place grounders and pop flies to their fielders for practice purposes. And with a fungo bat in their hands, some coaches can pull off wicked accuracy – as one story goes, the late California Angels player and coach Jimmie Reese once shot an 82 on an 18-hole golf course using nothing but a putter and a fungo bat.
×