Confirmed behavior
Flowermen are plant-warped humans that hunt in packs. Nests have bright orange flowers. Flowermen can lie still until disturbed and can trap nearby Active Matter.
Alpha Flowerman
The Gigastructure update introduced Alpha Flowerman. The official update confirms the name and addition; it does not establish a universal health value, timer or drop table in the source set.
Safer reading of screenshots
Use the official Flowermen image set for identification. A generic creature screenshot is not enough to name a variant.