Frog

Verified against the spelunky.ai port v0.1.10 on 27 October 2026.

Level generation puts Frogs on blocks all over the Jungle, under water as well as on land. A Frog doesn't move until the player comes within 64 pixels; then it jumps at him again and again, each jump carrying it several blocks, and bites him if it lands on him. With 1 hit point, it dies to any damage, whether from the Whip, a stomp or a thrown Rock.

A Frog sits still until the player is within 64 pixels of it, counting from the edges of the two, and then croaks and starts jumping ^[5]. Each jump starts from the ground at 2–4 pixels per step upward and 3 pixels per step (90 per second) across, toward the player, and it keeps that speed across until it lands ^[6]. A wall it hits sends it back the other way at 1 pixel per step, and a ceiling stops it rising ^{[7] [8]}.

Gravity adds 0.2 pixels per step to its fall every step, which brings it down again about 20, 30 or 40 steps after a jump at 2, 3 or 4 upward, so a jump carries it about 60, 90 or 120 pixels across, four to seven blocks ^[9]. In the clip, its first jump, at 3 upward, carries it 93 pixels and 23 high, clean over the player's head; its second lands on him ^[10].

When it lands, it stops dead and rests for 10–40 steps (0.33–1.33 seconds); if the player is still in range when the rest is over, it jumps again, and if not, it sits where it landed ^{[11] [12]}. It never walks: jumping is its only way of moving.

Water doesn't trouble a Frog: its gravity in water is the same 0.2 as in air, so it jumps and falls there as it does on land, and there's no drowning in its code ^{[9] [13] [14]}. Like most monsters, it only acts while it's on screen or just off it ^[15].

When the player touches a Frog without stomping it, he loses 1 heart, is knocked away from it, and blinks, invincible, for 30 steps (1 second) ^[16]. This is the touch code most monsters share; the Frog has no attack of its own, and the clip above shows a jump landing on the player and taking him from four hearts to three.

A Frog has 1 hit point, so any damage kills it ^[17]:

Frogs killed count toward the player's kills, and the screen between levels draws a Frog icon for each ^{[28] [29]}. One that Spikes, Lava or a Spear Trap killed doesn't count ^{[30] [31] [32]}.

Level generation makes Frogs only in the Jungle, levels 5–8, on top of blocks with open space above them, outside the starting room and shops, and not on a graveyard level ^{[33] [34]}:

• On land, a 1 in 30 chance for each such block, once the rolls for a Mantrap, a Caveman and a Fire Frog have failed ^[35].
• Under water, where the block has water above it, a 1 in 30 chance once the roll for a Fire Frog has failed ^[36].

Frogs also come from:

• Fire Frogs. A Fire Frog that lands in water turns into a Frog ^[37].
• Olmec's yellow balls, which turn into a Bat, Spider, Snake, Frog or Fire Frog when they hit the ground ^[38].
• Custom levels, as the level editor's tile f ^[39].

• A Frog doesn't move until the player is within 64 pixels, so one can be left sitting by keeping that far away.
• Each jump keeps its speed across until the Frog lands, so a player who steps aside while it's in the air is out of its way.
• A Frog rests after every landing, which is the moment to whip it.

• The Frog's code names a walking state and a drowned state, but nothing ever puts a Frog in either: it only sits, jumps and lands ^[40].
• A commented-out line beside its range check would have woken it at 48 pixels rather than 64 ^[41].