Hammer Bro.
From SMWiki
Hammer Bros. made their first appearance in Super Mario Bros. for the NES. They usually appeared in pairs, hence the "Brothers" in their name. Their basic behavior was established here: Walk back and forth in a fixed area, rapidly chucking hammers and occasionally jumping up. They were usually situated on two level brick structures where they could jump up or back to the ground. Bashing the bricks beneath them was the easiest way to defeat them, and they were much more deadly if encountered out in the open. The same basic behavior was used in Super Mario Bros. 3, but several additional varieties such as Boomerang Bros and Sledge Bros. were introduced.
For Super Mario World, Hammer Bros. were largely scaled back. The only true variety is the Amazing Flyin' Hammer Bro., which perches atop two winged grey turn blocks that fly in a swooping pattern. The Sumo Bros. might be considered another variant of the Hammer Bros. race, but they have completely different behavior. The Amazing Flyin' Hammer Bros. sprite is quite odd-looking: Instead of a segmented carapice like a Koopa Troopa, it has a smooth shell like a Buzzy Beetle. It has no beak or nose of any sort, and its eyes are small dots. Its body is entirely blue and it wears white gloves.
Hacking information
Amazing Flyin' Hammer Bros. are sprite 9B and their platform is sprite 9C. (They must be placed on top of their platform to work properly) They use blue palette B and their platforms use grey palette 9. Amazing Flyin' Hammer Bros. can be used in any area that Chargin' Chucks can. (That is, any level where SP3 is set to GFX13, so everywhere but castles and Ghost Houses)
Amazin' Flyin' Hammer Bros. will throw hammers at differing rates depending on which level they are in. In any level located on the main world map, they'll slowly drop hammers down. In levels located on any of the submaps, they'll quickly throw hammers in high arcs.
There are, of course, several varieties of classic Hammer Bros. available with Sprite Tool. By default, these replace the graphics for the Amazing Flyin' Hammer Bro. There is a glitch in Super Mario World where a hammer will vanish if it disappears off the top of the screen, so any brick platforms should be set at an appropriate height in order to avoid this.
