Boil is a trooper of the 212th Attack Battalion, introduced alongside Waxer in "Innocents of Ryloth" (6 March 2009) and voiced by Dee Bradley Baker.
He is the sceptic of the pair — the one who wants to complete the objective, points out that they are behind enemy lines, and is entirely right on the military merits. Watching him lose the argument is what gives the episode its weight, because the show has to earn the sentiment against a case rather than in a vacuum.
Catalogue entry. This figure has a verified record here rather than a full write-up — the encyclopedia labels its own depth instead of padding it.