Spirit terrorbird

A Spirit terrorbird is one of the most popular summoning familiars, as it can can carry up to twelve items and restore run energy with its special move, Tireless Run. It cannot hold untradeable Items, items that are deemed "too valuable" nor Rune essence or Pure essence. It requires 52 Summoning, and is the most common beast of burden because of its relatively low requirement, cheap pouch price and reasonable amount of storage.

Once summoned, the Spirit terrorbird will disappear after 36 minutes, dropping all of its inventory. The Spirit Terrorbird can hold up to 600k, making it better than a Bull Ant by holding 150k more.

Spirit terrorbird pouch
Spirit terrorbird pouch is made by using a Summoning pouch on a Summoning obelisk with 12 spirit shards, a Gold charm and a raw bird meat in the inventory. Making the pouch earns 68.4 experience points. Using the pouch to summon a Spirit terrorbird gains 0.8 experience points, and costs 6 Summoning points. If players exchange their Spirit Terrorbird pouches at Bogrog, they will receive 9 spirit shards per pouch.

Tireless run scroll
Tireless run scroll enables the use of the Tireless Run special move for a Spirit terrorbird. Using the pouch on a Summoning obelisk creates 10 scrolls.

Tireless Run
Tireless Run is a special move for Spirit terrorbirds, which:


 * Restores the player's running energy by half of the player's Agility level rounded up
 * Temporarily increases the player's Agility level by 2 levels.

Tireless Run is very useful when players have to run for a long time, such in the Summer's End quest, or while doing a special task like an Agility course or doing the Pyramid Plunder mini game, in which players have to do a lot of running in a short period of time. However, familiars are prohibited from entering certain places where unlimited run would be useful (For example, they cannot enter the Ape Atoll Agility Course, Dorgesh-Kaan Agility Course or the Brimhaven Agility Arena). Some players find Tireless Run useful when Runecrafting, particularly when using the ZMI altar or running Astrals. However, this cannot be used when runecrafting law runes, because Summoning familiars aren't allowed in Entrana. Unlike the abyssal familiars, it can't be used to carry rune or pure essence. Tireless Run is commonly used for Penguin Hide and Seek due to the boost to run.

It is also virtually essential when attempting to solo in the Saradomin Godwars, as Zilyana moves very fast, meaning you have to run constantly.

Trivia

 * The Spirit Terrorbird almost identically portrays an artist's impression of Gastornis, a prehistoric predator that lived 62-2 million years ago which was also nicknamed the 'terror bird'