I wish abbeythrowsstuff wouldn't mark a thread as resolved until it actually has been. The question was Please check that cows drop heads in Skyblock. She replied that they are not supposed to and then locked the thread, giving me no chance to reply and point out this:

Below are a list of challenges in SkyBlock, these are the full names for completing a challenge. To complete the challenge it is /c c challenge. Please post anything that needs to be fixed or moved below. headcollector (this challenge is currently not completeable since biome change is needed for the snow golem. There also may be 1 or 2 heads missing.)
- Required items: 1 zombie head, 1 skeleton head, 1 blaze head, 1 cow head, 1 pig head, 1 sheep head, 1 spider head, 1 creeper head, 1 magma cube head, 1 wither head, 1 bat head, 1 iron golem head, 1 snow golem head, 1 slime head, 1 ghast head, 1 chicken head, 1 zombie pigmen head, 1 enderman head, 1 squid head, 1 witch head

~ @MrsMegan

So MrsMegan made a challenge that's impossible to complete not only because the biome changer is not implemented yet, and shows no sign of being so any time soon, but because cows and sheep do not drop heads. A fact that I was unaware of as I waste time trying to get one for this challenge while I wait for the biome changer.

MrsMegan, please amend Head Collector so that it is actually completable. Please check that all the heads that are require are obtainable now and do not require a feature that Skyblock does not have.

Thank you.