Paper Hammer Bro
From the Super Mario Wiki
Paper Hammer Bros. are paper forms of Hammer Bros. that appear as enemies in Mario & Luigi: Paper Jam. Like with their regular counterpart that also appears, Paper Hammer Bros. throw hammers as their main method of attacking. Paper Hammer Bros. are commonly found alongside their normal counterparts in Twinsy Tropics Dungeon and Neo Bowser Castle. Stronger variants are also found in Sunbeam Plains.
Rare, shiny variants can also appear in place of the regular Paper Hammer Bros. in the same areas with greater stats. The ones in Twinsy Tropics Dungeon and Neo Bowser Castle will always drop a Supersyrup Jar and LV 1 Character Card when defeated, and the ones in Sunbeam Plains will always drop a Max Mushroom and a Shocking Hammer when defeated.