I have been in two games now — one with Tiny on my team and one on the opposing team — where he has taken over the game.
In both games, he was the sole person in the middle lane and proceeded to gank and become unstoppable really fast by feasting on opposing squishies. His avalanche + throw combo can 1-shot most non-tanky heroes, and once he gets blink dagger he becomes unstoppable.
What are some good ways to counter him and which heroes/items should I be looking at?
You need to recognize burst gankers like Tiny are a threat early in the game and adjust your play around them. Typically, this means that I'll be picking up strength Power Treads and/or a Bracer to give myself extra strength to survive. If the other team has multiple magic damage heroes, you can also look into picking up a Cloak or even a Hood or Pipe.
This should prevent Tiny (or Nerubian Assassin, or a few others when they're ported) from ganking you by himself, he'll need teammates or a truly massive advantage to do so. Tiny has powerful burst but after his combo (which deals ~900 magic damage, ~675 damage to standard magic resistance) plus the damage from a couple of autoattacks, if he hasn't killed you there's no way he should be able to: you have your own spells and hopefully aware teammates.
Other things you can do to prevent a Tiny from snowballing apply to every game: have good wards up at all times and help your middle lane rune control if possible. Limiting Tiny's early game mana really slows him down because he's not much of a threat without that 240 mana to combo. You can also put strong laners against him, since Tiny has such low base armor, and seriously limit his early game farm. Some common options to counter a solo melee hero in mid lane include:
Tiny initially relies on kills and level before it takes over a game. Avoid giving kills to Tiny early game. Try not to give him runes on the either side and keep an eye on tiny's mana in lane, it helps a lot.
In addition to above said hero's in my opinion if you really want to counter tiny safest way get Silencer, keep using curse initial game and you will be fine.
Though everything depends on other players and your team, it is not necessary that a particular strategy will be successful every time.
Heroes that would be usefull for you:
.Rikimaru: Allowing you to either "blink strike" in an enemy/friendly foe away from Tiny once you see him or using your "smoke bomb" to increase his chance to miss his toss/avalanche
. Naga siren: You can put him to sleep using your ultimate once he blinks to battle
. Yurnero: Once he blinks, you can spin, making you imune to magic + dealing some good damage while he tries to toss/stun you
. Faceless Void : Ultimate will keep you safe
. Omniknight : Enough life to survive the burst + ultimate to keep you and your allies alive + healing/AoE damage + Movement Slowed, making him even much slower
. Morphling : Wave Form to run away
Items : . Black King Bar : Using it, allows it to stay immune to Magic . That sword that burns mana,i just forgot its name, usually tiny does not have lots of mana,so, if he missed the first try, you can burn his mana away
Just to name a few, thats all i could think by now, hope it helps.
Firstly, anti-mage. he is simply the best against tiny. his spell shield, his mana burning etc...
Secondly, juggernaut. the way he is immune to magic when he spins is ridiculous.
Furthermore, like said before, void is just epic. You use his ulti, you run in, hit him a couple of times while another team mate knocks on a couple of spells and he's toast.
Finally, one last mention to diffusal blade and bkb. diffusal blade for mana burning and the bkb for magic immunity. u could actually get a cloak -> hood -> pipe
tiny has very low mana pool so get someone like silencer and spam your mana burn early on, as for late game what you can disable his ability to snowball if you can get orchid early on that way he can't do anything other than right clicking for a period of time try to kill him as fast as possible on that time, for the carry i think it's easy to assume every carry needs a bkb no matter what if not for the opponent's spells than for their items they might get such as orchid, vyse or dagon, don't try to take tiny on by your self no matter what, see him as a threat at all times he gets HUGE damage from his ulti so never take him on by your self have at least 1 person with you early on, if tiny goes mid than make sure a disabler smoke gank him on lane stage frequently that way he can fall off and have no effect later on.
If Tiny goes for a magic burst, he is not very strong in the late game. A melee carrier with a BKB will counter him very well. Range heros like sniper can kite him with eye of skadi. Don't try to clash because he is strong. Ward defensively and keep farming.
However, if Tiny builds a scepter and physical DPS, he can counter almost all melee carriers. (with his clever and E stun)
