Octopamine (β,4-dihydroxyphenethylamine) is an endogenous biogenic amine that is closely related to norepinephrine, and has effects on the adrenergic and dopaminergic systems. It is also found naturally in numerous plants, including bitter orange.Biosynthesis of the D-(–)-enantiomer of octopamine is by β-hydroxylation of tyramine via the enzyme dopamine β-hydroxylase. Under the trade names Epirenor, Norden, and Norfen, octopamine is also used clinically as a sympathomimetic agent.

Octopamine was first discovered by Italian scientist Vittorio Erspamer in 1948 in the salivary glands of the octopus and has since been found to act as a neurotransmitter, neurohormone and neuromodulator in invertebrates. It is widely used in energy-demanding behaviors by all insects, crustaceans (crabs, lobsters, crayfish), and spiders. Such behaviors include flying, egg-laying, and jumping.

The best-understood role for octopamine is in the locust jump. Here it modulates muscle activity, making the leg muscles contract more effectively. This is at least in part due to an increase in the rate of contraction and of relaxation.

John Czawlytko (born February 22, 1963), better known by his ring name Max Muscle, is a retired Polish professional wrestler best known for his appearances in WCW in the mid-late 1990s.

Czawlytko began his career in 1992, wrestling under the ring name The Brute as part of the tag team the Skull Crushers along with The Beast (Bryan Carreiro).

He first appeared in WCW in 1993 under the name Big Bad John, making appearances on WCW Saturday Night, WCW Main Event and WCW Pro. In 1995 he was repackaged as Diamond Dallas Page's bodyguard, Max Muscle, memorably helping Page cheat in arm wrestling contests. In 1996, Muscle joined the Dungeon of Doom faction, shaving his hair into a mohawk and using the name Maxx.

Czawlytko retired from wrestling in 2002.