Legendary Creature — Squirrel
This spell can't be countered.
Indestructible
Toski attacks each combat if able.
Whenever a creature you control deals combat damage to a player, draw a card.
1/1

Draws a card whenever your creatures deal combat damage to players.

Same combat-damage card draw trigger, plus forces opponents to attack.

Draw on combat damage to players, green-adjacent style card advantage.

Card draw engine off creatures, similar repeatable advantage.

Green creature-based draw engine for the same go-wide decks.

Continuous green draw engine when creatures enter.

Draws cards when creatures deal combat damage to players.

Green enchantment giving draw on combat damage and trample.
A spell or ability that counters spells can still target Toski. When that spell or ability resolves, Toski won't be countered, but any additional effects of that spell or ability will still happen.
If Toski can't attack for some reason (such as being tapped or having come under that player's control that turn), then it doesn't attack. If there's a cost associated with having it attack, you aren't forced to pay that cost, so it doesn't have to attack in that case either.