During the devotion quest chain for your god, usually 3rd (may vary) in a Deity's line, one of the rewards is a summoned noncombat buff pet. The buff from the pets scale to your level.

Update: As of GU61, all pets now give +boost to all 5 stats (STR, AGI, INT, STA, WIS). This will still scale by level (listed below). If you have access to the 'Shadows' AA tree, you can buy upgrades to enhance this (1aa=+10%, max 5pts). 5AA gives +50%, taking the L90 of 38.5 to 57.7.

stats by level

Level	+boost
50	?
55	21.5
60	?
70	?
80	?
90	38.5

Deity Pets

Deity	Pet	Race	Release
Good
Mithaniel Marr	Valiant Beast	Lion	EoF
Quellious	Peaceful Visage	Air Elemental	EoF
Tunare	Friend of Growth	Wisp	EoF
Rodcet Nife	Healing Companion	Valkyrie	TSO
Neutral
Bristlebane	Beloved of Bristlebane	Bovach	LU38
Brell Serilis	Underfoot Attendant	Earth Elemental	EoF
Karana	Child of Karana	Water Elemental	RoK
Solusek Ro	Minion of Ro	Imp	EoF
The Tribunal	The Tribunal's Bailiff	Shrouded Figure	RoK
Evil
Bertoxxulous	Pariah of Bertoxxulous	Carrion Golem	RoK
Cazic-Thule	Servant of Thule	Lizardman	EoF
Innoruuk	Minion of Hate	Mummy	EoF
Rallos Zek	Warrior of Zek	Giant	EoF
Anashti Sul	Undying Servant	Void Beast	TSO

Can now be hidden with /pet hide