Juan Carlos Argüello (23 September 1965 - 1 July 1995), known as Muelle [ˈmwe.ʝe], was a Spanish graffiti artist from Campamento, Madrid.

Many other Madrilenian youths, known as flecheros created their tags inspired by Muelle's, often ending strokes with arrowheads (flechas).

The flechero scene developed at a time of cultural isolation, its practitioners being largely unaware of graffiti in the New York style.

[6] In 2022, the Spanish graffiti brand Montana Colors released a special edition aerosol can featuring Muelle's tag alongside a short documentary about him.

[7] At the behest of local PSOE politicians a tag of Argüello‘s in La Latina, threatened with obliteration by building renovations, was officially protected by the Government of the Community of Madrid in 2024.