The Lord gave Peter a wonderful vision:
"And saw heaven opened, and a certain vessel descending unto him, as it had been a great sheet knit at the four corners, and let down to the earth: Wherein were all manner of fourfooted beasts of the earth, and wild beasts, and creeping things, and fowls of the air." Acts 10:11-12
The animals shown in the vision included:
fourfooted beasts
wild beasts
creeping things
fowls of the air
And of the above animals the Lord commanded Peter saying: "Rise, Peter; kill, and eat But Peter said, Not so, Lord; for I have never eaten any thing that is common or unclean." v13-14
Based on Peter's response, we can draw some conclusions as to just what animals God showed him. Here are 3 options:
common animals
unclean animals
both common and unclean animals
However, God's response to Peter was even more specific in that He said: "What God hath cleansed, that call not thou common." v15. God did not address the unclean animals because it was not part of the animals shown to Peter in the vision, but God did address Peter calling the animals shown in the vision to be common animals that Peter never ate before.
Based on God's response, the fourfooted beasts, wild beasts, creeping things, and the fowls of the air are part of the common category.
Here is a list of few common animals that Peter likely have never eaten before: roebuck, hart, the fallow deer, wild goat, pygarg, wild ox, chamois, locust, bald locust, beetle, grasshopper etc... Suppose God shown you these animals in a dream and command you to eat it, will you respond in the same way by saying you have never eaten them before?
In what way did God cleanse these animals so that they are edible? By His word.
"Notwithstanding thou mayest kill and eat flesh in all thy gates, whatsoever thy soul lusteth after, according to the blessing of the LORD thy God which he hath given thee: the unclean and the clean may eat thereof, as of the roebuck, and as of the hart...Even as the roebuck and the hart is eaten, so thou shalt eat them: the unclean and the clean shall eat of them alike." Deuteronomy 12:15,22
There are 2 types of unclean animals, one which God permits to eat, and one which God forbids to eat:
Unclean in the sacrificial sense: not good enough to sacrifice it unto God but good enough to eat "Thou shalt eat it before the LORD thy God year by year in the place which the LORD shall choose, thou and thy household. And if there be any blemish therein, as if it be lame, or blind, or have any ill blemish, thou shalt not sacrifice it unto the LORD thy God. Thou shalt eat it within thy gates..." Deuteronomy 15:20-22
Unclean in the hygienic sense: not good enough to sacrifice it unto God and not good enough to eat. Such as, pigs, mouse, etc.. "They that sanctify themselves, and purify themselves in the gardens behind one tree in the midst, eating swine's flesh, and the abomination, and the mouse, shall be consumed together, saith the LORD." Isaiah 66:17
In conclusion, God did not command Peter to eat pigs, mouse or bats in his vision. But God command Peter to eat some of the common animals that Peter never ate before.