You can feed a pig 4 monster meats and attack it with a spear while it's transforming. The transforming animation is enough time for you to kill it but be warned that other pigs will attack you if you are close to them.
ALSO! for fleshy bulb put them near pig/ rabbits or any thing good, (beefalo) snd the eyeplants will do all the work for you, you just go in and eat! (but NEVER kill and eyeplant, the meat goes away and then you have to kill th bulb and it takes time to re spawn more eyeplants,) try looking it up on the Wiki.
Great way to make a meat farm is to make a Hammer and destroy pig houses, then get the materials and build a pig house near your home and when the pig comes kill it, wait for next, kill it, and keep doing it but it takes a couple days for a pig to respawn and this ALSO works with Bunnymen!