- Turboworms are an alien lifeform in Generation One
Turboworm wrestling is a particularly macabre form of entertainment native to Rigel 6. For the price of an admission, spectators get a dose of unadulterated carnage served up courtesy of the Grease-pits.
The term 'Grease-pits' is generally associated with mechanoid blood sports, so Turboworms are probably mechanical lifeforms. Alternately, the sport could feature mechanoids wrestling the dangerous Turboworms.
Marvel Comics continuity
Prior to the Ark's launch 4 million years ago, Grimlock and Sludge saw turboworms wrestle on Rigel 6. The dim-witted Sludge thought the proceedings quite fun, but Grimlock had a noticably more chilled response to the pointless slaughter, merely calling it interesting.