The four-angled, branched stems of Euphorbia enormis tend to be contorted or twisted, possibly attempting branching that doesn't succeed. The smooth, green surfaces usually have some paler, often feathery markings.
Spine shields along the slightly wavy stem ridges are discontinuous, each forming the base for a pair of rigid spines angled out like some cattle horns. A spine becomes about 8 mm long. Young spine-pairs are pale red-brown for a short period. Older, dry spines are whitish grey, the pair often imbalanced from early damage.
The rudimentary leaves on young growth drop off early (Frandsen, 2017; iNaturalist; http://www.llifle.com).