Not to be confused with the [[NSC/uMon Upgrade|uMon "upgrade"]] to which captured feral mons are subjected as part of their enslavement.

There are various ways by which mons may be upgraded or modded to change their form and capabilities. 

== Mod Packages ==
Mons can be upgraded with a mod, either Official or Third Party. Most mods are simple things like cosmetic or stat alterations, but there are various Mod Packages which are more extensive. Most of these are limited-time official packages sanctioned by uMon, but some of the most adventurous and skilled third-party modders have put together Mod Packages as well.

Most Mod Package mons can be identified by a name of the form "(Adjective) (Basic Mon Name)," e.g. "Lunar Spronget."

Many mod packages can be purchased from uMon or their third party creators. Others were limited-time-only and are no longer available, or given out as contest prizes or for promotional purposes. Thus, they vary greatly in availability.

Official Mod Packages include, e.g. Winged Salamandramon, Hyacinth Loromon, Grey Loromon, Unanchored Celestine, Moonlight Hoopoon, Sunlight Hoopoon, Cursed Panzermon. 

Third Party Mod Packages include Forest Fire Mkodomon (later an official mod package), Mod Petrelmon, Security Velocimon, Iron Imvubion, Slugtron

== Ultra System ==
uMon offers some mon upgrades that are part of the Ultra System. A special item called an Ultra Key upgrades selected mons. Not all mons have an Ultra System upgrade; in fact, it's only a small subset. uMon gives away Ultra Keys as contest prize items. They also sell for exorbitant prices on the secondary market. An Ultra Key can be used on any Ultra System mon, but once it is used on a particular mon, it can never be used on another. The Ultra System upgrade only lasts for the duration of a single battle, but the Ultra Key can be renewed by uMon for a fee of $N1000.

Most Ultra System upgrades consist mainly of well-rounded stat upgrades. Because of the need for the upgrade to take place rapidly and without regeneration equipment, Ultra System upgrades tend to be physically minor.
Ultra forms of mons generally start with an intrinsic making them [[NSC/Empowered|Empowered]] for several turns.

Mons with Ultra System Upgrades include Ignione, Panzermon, Velocimon, Anuramon, Platarmon, Razorrat, and Scorpene.

== Advanced Form ==
Some mons have an "advanced form," which is an upgrade that can be purchased at any time, providing the mon has reached a certain experience level. The difference between an Advanced Form and an official Mod Package is mostly a marketing one, though advanced forms tend to change the basic mon design and theme less than Mod Packages.

Mons with Advanced Forms include Goylemon (Goylemakht, Goylegikh), Deinomon (Deinomoar), Castrolob (Castrotroll), Sporedrop (Sporedrill), Salamandramon (Salamandragon), Sandpup (Sandpop), Strygamon (Strygalich), Electrawuff (Electrawarg), Rootbom (Rootmyne), Durimon (Duriking), Capriroc (Caprihorn), Pyreed (Pywrap), Bheloot (Bhelzephl), Hippocamon (Hippocalamatus), Norzmon (Norzherre), Stemodile (Steamagator), Embunny (Embrabbit), and Miniphant (Megaphant)