The lancero is a spear: long, skinny, usually with a small ring around 38. Some wear a pigtail cap. It is a parejo that behaves like a specialist size. There is not much room in the bunch, so ligero has to be used with care and the wrapper does a lot of the talking.
They are slower to roll and easier to damage. Houses that still pack them tend to treat them as a craft size, not a volume size.
If you want the opposite silhouette, see toro or robusto. Same tobacco family, different geometry.