Tame 3 Carnos, drop the Troodon in a cage with a ramp, hit the Carnos til they are almost dead, put them on neutral, walk with them into the cage, watch their hp with "H" and dismount right before the Troodon kills them.
Troodons use a unique flavor of Passive Taming. Instead of putting a Food item in your last Inventory Slot, you have to instead allow the Troodon to kill your tames. Troodons gain Taming Affinity by earning Combat Experience, with the amount required reduced to 40% at night. Taming Affinity will only be credited to a player if the creature killed belonged to you or your tribe. A singular tame is capable of providing experience to multiple Troodons. Tests have shown this is unreliable, but can be reproduced.
Experience required: 343 + (32 x Troodon's level)
Experience required at night: 137 + (13 x Troodon's level)
Creatures must not be set as Passive and must be unmounted by a player.
Creatures can be unconscious or pre-damaged (i.e. at 1 Health remaining).
Babies and adults provide the same amount of experience.
Pheromone darts may be utilized to make the Troodon attack a chosen dino, but be careful that other wild dinos do not enter the fight.
There is a "Feeding Interval" of sorts, wherein no Taming Affinity will be gained for subsequent kills. It is not yet known how this is calculated, but 90 seconds was sufficient for a level 1 Troodon.
Taming Affinity will not reset nor is Taming Effectiveness reduced when a wild Troodon takes damage.
In fact, Troodons will always tame with 100% Taming Effectiveness (i.e. 50% bonus levels).
Taming and Experience Multipliers do not seem to affect the Troodon. That said, the table below utilizes the v253.0 hard-coded 2x experience values (although even if the actual amount of experience required and earned is still on the previous 1x values, the taming requirements are the same.
Troodons will not readily aggro onto most creatures that provide a substantial amount of experience. To circumvent this, have the Troodon aggro to the player while standing on top of the creature