magic the gathering tag block?

To combine the first two answers...yes, and if the 5/5 has Trample, it will prevent 4 of 5 instead of 2 of 5 damage.

To expand...if the creature has no abilities listed (or the abilities of the blocker[s] supersede the attacker's [i.e.: defender has Reach against an attacker's Fly ability]), you can block the 5/5 with a SINGLE 2/2 (unless the attacker has the ability to require multiple blockers, or you opponent has a card in play requiring you to block with multiple blockers).

The difference is that you'll still have a blocker next turn, and that may give you the extra turn to find that Giant Growth card that will allow you to kill the 5/5 with the 2/2.

The only advantage the two blockers will give is if you can get a card that can do one or more points of damage to the attacker before the end of his turn, you can kill it (since Damage Resolution takes place at the EoT!).

Good Luck!

This is indeed a legal block, but there are only a few reasons to do this. If you have a boost spell or a way to stack 1 damage, that's fine. Or also, if you are blocking a creature with trample, this will reduce 2 more damage than just one creature blocking.

In short, unless the creatures have a static ability stating they cannot block/be blocked or a way to give them these abilities, your block with the two 2/2 creatures is perfectly legal.

Yes you can as long as it a legal block but why. Using two 2/2 creatures on a 5/5 is kind of useless as you will loose both your creatures and the 5/5 will still be there.