Given the task definition and input, reply with output. In this task, you are given a set of context paragraphs, some supporting facts and an answer of a question. Your task is to generate question for given answer based on set of context paragraphs, supporting facts and an answer.

Context_1 : Tough Trucks, also known as Tuff Trucks, Pro Arena Trucks and, Street Warriors, are off-road truck competitions held at 4x4 truck jamborees and monster truck events. Tough Truck competitions are a downsized form of short course off-road racing. They are run as a side act at most monster truck shows. Depending on venue and promoter, the tracks can range from as big as a football field, to as small as a hockey rink. Most track set ups consist of a handful of double jumps, single banzai jumps, uneven/rocker hills, and dirt kicker ramps, again depending on venue and promoter. Some tracks are run in Chicago Style/Round E Round Track or S-Style Track. Some competitions are run as a single pass time trial, or side by side racing. Context_2 : Trucks and Tractor Power was a long running weekly television show on TNN featuring mud bogging, tractor pulling and monster trucks. The show's original hosts were Stan Rhoads and former Bigfoot driver Rich Hooser, along with pit reporter Mike Goss. Gary Lee replaced Stan Rhoads. Army Armstrong later joined as a pit reporter, and later, when Hooser left the show, became color commentator. The show initially began in 1989 as a vehicle for TNT Motorsports events, complimenting their ESPN show Powertrax and syndicated show Tuff Trax, and would typically alternate between truck and tractor pulls and monster trucks, with National Mud Racing Organization mud races intermittently. After TNT was bought out by the United States Hot Rod Association in 1991, the show began primarily airing the Pendaliner Monster Truck Series and NMRO mud races held at Special Events' 4-Wheel and Off-Road Jamborees. A frequent feature of these shows was a highlight segment of "Tough Truck" amateur off-road races near the end of the monster truck episodes. The final season of Trucks and Tractor Power had Gary Lee as the host at the Monster Truck Thunder Drags, with Dave Rief, and later Tom Rivers, for the Jamborees. At the end of the 1996 season, the Pendaliner cancelled their sponsorship of the monster truck series, causing the show to be subsequently cancelled. Context_3 : Dennis Anderson (born October 24, 1960) is an American professional monster truck driver. He is the creator, team owner, and former driver of "Grave Digger" on the USHRA Monster Jam circuit. Anderson is from Kill Devil Hills, North Carolina, where he currently resides. Context_4 : A monster truck is a pickup truck modified with a larger suspension and larger tires, usually for recreational uses. Today pickup trucks are still used, however SUV bodies as well as themed trucks are driven and most of the bodies are now made of fiberglass rather than metal. Themed trucks vary from car bodies, SUV bodies, and even animal themed bodies. A competition monster truck should meet guidelines by being 12 feet tall, 12 feet wide, and as of 2015, should be equipped with specifically made 462lb BKT 66-inch off-road tires. Monster trucks used to be side acts at popular motocross events and mud bogs but today they are usually the main attraction with motocross and mud bogging being the complementary shows. Context_5 : Monster Nationals is the name of the monster truck series run by Image Promotions. The series primarily consists of monster truck racing and freestyle in indoor arenas. The events typically have only two parallel sets of cars on an empty concrete floor as a race track. The event format is similar to those of the USHRA Thunder Nationals series, due to owner George Eisenhart being the former director of that series. Trucks currently running in the series include Big Dawg, Lil' Miss Dangerous, Nitemare, Raminator, and Rammunition. In previous years, Bigfoot also competed. Unlike its USHRA counterpart, the Monster Nationals series runs indoor arena shows during the winter season and outdoor fairground shows during the summer. Some monster trucks that are new to the Monster Nationals include Tailgator (Doug Noelke's newest creation), Holman's Beast and teammate truck Ironman, and more. Returning trucks to the circuit include War Wagon, formerly owned by Jeff Cook who sold it to Andy Hoffman, and Samson, who ran the outdoor series in 2003 and 2007. The Monster Nationals, along with intense monster truck racing, also features some extreme stunts and performances such as a jet-powered Jeep, a jet-powered recliner, FMX Freestyle, BMX Freestyle, and car-eating transformers. Context_6 : Grave Digger is a monster truck racing team in the Feld Entertainment Monster Jam series. There are nine Grave Diggers being driven by different drivers to allow them to make appearances at more events, but their flagship driver is creator Dennis Anderson. Dennis Anderson is the head of the Grave Digger department team. He is in charge of the training of the younger drivers and the fleet of trucks. Grave Digger is considered to be one of the most influential and iconic monster trucks of all time. Context_7 : Thunder Truck Rally (released as Monster Trucks in Europe) is a monster truck racing video game developed by Reflections and published by Psygnosis where players select a monster truck or otherwise 4X4 vehicle equipped with monster truck tires and have the option of either racing or crushing cars in an arena. Context_8 : Adam Anderson (born December 5, 1985, in Norfolk, VA) is an American professional monster truck driver. He currently drives the monster truck "Grave Digger" on the USHRA Monster Jam circuit. Adam is the son of Dennis Anderson, a monster truck driver and 4-time Monster Truck World Champion. Adam currently resides in his home town of Powells Point, NC. Context_9 : Black Stallion is a monster truck that races on the USHRA circuit and for other promoters. Black Stallion started out as a stock 1982 Ford F350 back in 1982, owned and modified by Michael Vaters. The first modification was a homemade 12" lift kit, since such kits were unavailable at the time. Mike then later added two sunroofs, an Alpine stereo system, a Ford 460 Engine, Rockwell 5 ton toploaders, Clark 20 ton planetaries, 66" terra tires, a 9" television and later on, a 1988 Ford F series front end. Between 1990 and 1991, Mike realized the future of monster trucks, which was racing. To be competitive, Mike replaced the leaf springs with airbags, the old heavy split ring rims with lightweight one piece rims, fiberglass body pieces, cutting the tires, gutting the interior out, 4 linking the truck and putting in a bigger engine. The modifications proved to be beneficial to Mike, with close races with First Blood, and competing in some Pendaliner Special Events racing events. After a violent rollover in Bloomsburg Pennsylvania in 1991, Mike decided to put King shocks on the truck, which he later added coil springs in 1992. Along with the coil springs, Mike also removed the airbags. Mike is credited as the first owner to use bypass shocks. Also for 1992, Mike changed the front clip to a 1992 Ford F-series front end. Mike rarely ran this truck after he built the popular Boogey Van in 1993, driven by his then wife, Pam Vaters. Due to this, the truck was nicknamed Rodney, after the comedian, Rodney Dangerfield. Mike then built a truck for the 1996 season for research and development, named Black Stallion 2000, since his crew members joked about Mike not building a new truck for himself until the new millennium. This chassis is still running strong to this day. For his 20th anniversary, Mike decided to repaint Black stallion, with the front of the truck yellow, going into black with a horse face painted on. The truck currently has the same paint scheme. The drivers for 2016 are Michael Vaters & Matt Cody. Vaters will compete in the Fox Sports 1 Championship Series. Cody will travel to Birmingham, Toronto, Newark, Charleston, Columbia, Worcester, Wheeling & Baton Rouge. Context_10 : Blue Thunder is a monster truck that raced in the USHRA Monster Jam series. It was sponsored by the truck division of Ford Motor Company and Live Nation. The truck has several similarities with the monster truck Bigfoot. Some fans saw Blue Thunder as a replacement for Bigfoot in the Monster Jam series. The truck had been moderately successful and won several major events during its existence. However, it has not yet won a championship. Blue Thunder is used by Ford Motor Company for promotional purposes along with competition. The truck is currently driven by Matt Cody. The truck did not compete in 2012 when Todd LeDuc moved to Metal Mulisha after driving Blue Thunder in 2011. The truck was brought back in 2013 with a veteran driver, Dan Evans; who use to own and drive Destroyer, then Team Hot Wheels, as well as a new paint job. fact_1 : Dennis Anderson (born October 24, 1960) is an American professional monster truck driver. fact_2 : He is the creator, team owner, and former driver of "Grave Digger" on the USHRA Monster Jam circuit. fact_3 : Grave Digger is a monster truck racing team in the Feld Entertainment Monster Jam series. fact_4 : Grave Digger is considered to be one of the most influential and iconic monster trucks of all time. Answer: Grave Digger
Dennis Anderson is a professional driver known for driving which monster truck considered to be one of the most influential and iconic monster trucks of all time?