Encounters will depend on the type of scenario you want to play. In a post apocalyptic world there is huge scope for mutant or evolutionary animal and plant life, from intelligent cockroaches to triffids.
There is no reason that mechanoids themselves cannot make informed decisions about how they wish to live their lives, similar decisions to how humans did, so there can be a whole range of different types of mechanoids. The Three Laws are merely a guideline for most mechs, especially if there are no humans left alive.
Black Ice - vampiric mechs who feed on other mechs.
Reds - predators, who hunt down and scavenge off other mechs.
Greenies - herders and pacifists who lead communal life styles.
Whiteys - planters, power storers who develope extensive farmlands.
Yellows - decomposers, recyclers who scavenge from the dead and debris left behind.
Brownies - scavengers and salvagers, leading solo lifestyles.
Feral Mechs - mechs that have to some degree degraded their Three Laws and have adopted a "go-it-alone" attitude which tends to be hostile to most others. Ferals may form small groups or tribes as well.
The following information is for the "Moon is a Harsh Mistress" scenario, but can be used elsewhere.
Crazy - someone right off the deep end, even by inmate standards.
Radiant - a Variant who has been illuminated into the Church of the Celestial Moon, a cult type organisation gaining popularity, also called a Rad. (Psychic)
Witch Doctor - someone skilled in the construction and repair of mechanoids and robots (Mad Scientists)
Zorba - a mutant human being who has absorbed too much radiation or toxic waste and has mutated into something monstrous.
Martian - alien life forms who have begun appearing and are orchestrating a secret plan of their own. Martians have very advanced forms of biological technology and are hostile (xenophobic Martians) toward mechanoids. Martians come in various colours, the normal warrior class being reddy-brown, whilst the leader class are black. They are small humanoids with overly large heads, they like to wear heavy helmets.
Silk Worms - take over bodies and become Space Zombies, able to produce Space Silk which can be used to make space suits of remarkable toughness and resilience, and self repairing.
Space Zombies - possessed by Worms, protected by space silk.
Space Zombies from Mars - organic constructs made by the Martians and laced with bio-organic technology to keep them going. These materials degenerate quickly.
Rock Wallabies - life form that uses layers of rocks to form a protective shell against the vacuum, roll around the plains in herds.
Space Wraiths - an energy absorbing light based life form who follow the sun and hate shade.
Black Mist - negative energy life form that hides from the sun and hates positive energy, able to spit negative energy balls.
Borers - a form of worm that is able to bore its way through the lunar underground. They have now grown to enormous size due to mutations and the lower gravity. Borer tunnels are now much sort after as settlement locations due to their superior construction and their likely proximity to rich mineral fields or underground water.
Colony Bacteria (Swarms):
The moon is home to a number of advanced mutated life forms that were shipped up from the earth. These are mostly bacterial forms who have formed symbiotic colonies that use a combination of properties to form a viable life form. Nearly all of them include a bacteria that is able to convert sunlight into food. Colony bacteria come in sizes from small patches a few inches across to large mobile forms upto several metres across. The manner in which they move themselves varies from colony to colony, most crawl along the surface, but others seem to be able to manipulate gravity and float across the landscape. All colony bacteria are attracted to metals, especially heavy metals and rare earths and will mindlessly seek them out.
All colony bacteria are treated as swarms.
Floaters - bacterial life form that creates bubble like habitats that can manipulate gravity and magnetic fields and float freely over the landscape.
Slime - acid waste slimes, colony creature that lives by dissolving rocks and using sunlight.
Slinkies - colony bacteria that propels itself across the landscape by rolling or flopping.
Slug Swarms - a semi-sentient colony bacteria able to form small life forms of their own with toughened exoskin, attach like leeches to suck water.
Bogs - are areas of land where bacteria live and survive by absorbing whatever falls into their clutches. Able to use tentacle type attacks to drag passing prey into it.
Savage Worlds games all use an Adventure Card deck to give players one off advantages during the session. A base Adventure Card set can be purchased from the makers of the Savage World game, and can be used as a template for adding extra cards. Following are some suggested extra cards you might include in your deck (I like to have an 80 card deck so I usually add 30 cards to the base one).
1. Bountiful Resources: player may nominate one resource as being present in a reward and one unit of that material will be found. Further he will use a dice one better than they normally use for rolling on that reward, so d6 becomes d8 etc.
2. Aliens made me do it: this can be used as an excuse to escape from some embarrassing social situation, it may however leave a lasting stigma on you.
3. JOKER: play this card and you count as having a Joker till the start of your next action.
4. CURSED: playing this card allows your team to play another adventure card for free, however a permanent curse/virus/fault will be assigned to something you own by the GM. Whenever any of your dice show a 1 whilst using that item the curse acts.
5. Peaking Biorythmes: all skill rolls during the current encounter are at +1.
6. Streetwise: you gain +2 to a single Streetwise skill roll, and you gain an extra adventure card.
7. I'm not dead yet! Instead of dying you go into a coma.
8. Reload: find an extra ammo clip/energy pack for your weapon.
9. Cleansing: remove one addiction you may be suffering, or remove half of your current radiation levels.
10. Burst of Speed: you gain +4 speed and use a d10 for running for one round.
11. Bonanza! Double the amount of materials you find from one reward.
12. Berzerker: you go berserk immediately.
13.Action Man: you gain the effects of a Quickness spell for 1 round.
14. Heightened State: you gain the Quick edge for one encounter (if you have it you gain Level Headed instead etc).
15. Benny a day...: you may remove bennies to remove wounds or fatigue, one for one.
16. Dumb Luck: increase your wild dice one level for one encounter.
17. Kill Fest: the first player to gain 10 kill shots in this encounter gains a benny.
18. New Haircut: gain +1 CHA for one game session.
19. What If? You gain one combat edge for one encounter (lowest level).
20. Heart and Soul: on a successful attack you may take wounds to inflict a similiar number on your enemy, on top of whatever the attack does normally.
21. A Hearty Breakfast: you gain +1 Toughness for one encounter.
22. Super Sneaky: you gain +1 to all stealth rolls for one session. May hand in the card for a benny.
23. Emergency Cover: step behind any adjacent creature and they suffer the ranged attack instead of you.
24. Mulligans: redeal all adventure cards, must be played at the start of the session.
25. Serendipity: one of your programs that you are developing is progressed two stages (eg Alpha to Beta to Gamma) with no bugs or features.
26. Lucky Item: one of your items gains the Luck Edge for a moment, it gains a single benny. That benny can be expended to reroll any skill roll done with that item.
27. Acrobatic: when you suffer a knockback or flip you instead gain a free move action, taken instantly, and one that does not tirgger any opportunity attacks.
28. Freeze: do absolutely nothing on your turn and you may nominate a single other character within 5 inches, and they also do nothing on their next action. Should the cards give you an action before your target has missed their go you must hold until they do.
29. Luke, I am your father! You have to come up with some famous quote that is totally ludicrous but strangely relevant to the current situation. You gain a benny if everyone is amused by it. It may even be adoptable into the story if really appropriate.
30. Feast of Luckiness, you are able to access the bennies of anyone at the table, other than the GM.