The HF-61 has a heptagonal body or a septagonal body whatever you want to call it and has a yellow circle inside. On that circle there are seven trapper turrets and looks like a Trapper-7. On each side there is a very short Chiller cannon and on each edge there is a Vulcan turret.
It has freezing turrets which help it too. It also is very strange because most bosses deploy traps on the auto layer instead of the inside, thus making it very unique.
Currently does not spawn.
Keep in mind that it does have a lot of DPS and can take down teams really easily, thus making you needing alot of defense and offense. You will need around 7-9 hexa-builders to fend off the bullets for a while, around 3-5 surges to lower it's DPS to something really low. a lot of the freezer-class to freeze it completely, as well as Disintegrators to melt it's health. Any searcher branch for break traps and dealing damage, chain gun also works fine. This should be enough, but it will SLOWLY drain it's health if it does have a lot so get some minigun-class tanks to melt it's health very fast, formaldehyde works fine too.