The Lobelot is perhaps one of the most common creatures in SWTOR but also one of the rarest pets you can earn in game.
There are actually a variety of ways to earn this cute little purple frog pet in game as well. The rarity of this pet comes from the fact that you must be lucky and “generate loot” in the purple quality drop pool, which usually involves rewards such as companion gifts, yellow/orange crystals or crafting schematics.
As you can see from the image above, a player was kind enough to send me a screenshot over discord of them finding it as loot when killing level 1 K’lor’slugs on Korriban when levelling.

While there is no specifically best method, many players that I contacted for research or asked around in the community seem to have 2 common goalposts if you’re looking to earn your own little Lobelot legit.
The first is by killing easily farmable worldbosses, such as Lucky the Rancor on Corellia or the Primal Destroyer on Belsavis. As these bosses are farmed often by endgame players to earn currency or for events such as the Feast of Prosperity where they may be a quest objective.

The second is by farm killing large groups of easy to kill enemies, usually found in clusters on starter planets, capital worlds and sub level 20 locations such as Taris or Tatooine, this is most likely due to the fact that groups of enemies are indipendently easier to kill 1 on 1 and each one has their own generated loot pools.
Alternatively over the years players have reported looting the pet from Security Chests on planets or earning the Lobelot as a reward from Treasure Hunting crewskill reward item caches.

If farming isn’t your style, you are able to buy a version of the Lobelot from the Bounty Brokers Association event Vendor in the Cartel Bazaar for a few Bounty Contracts per character.